Q.If (3x+1, y−32)=(35, 31), find the values of x and y.
Concept understanding — Ordered Pair Equality
Ordered Pair Equality: From Intuition to Precision
Think about a simple list of two things — say, your name and your age. If I write (Ravi, 15), that's an ordered pair. The word "ordered" is the key: the first position and the second position mean different things. (Ravi, 15) is not the same as (15, Ravi), because the first one tells you a name first, the second tells you an age first.
Now, when are two such pairs equal? Intuitively, they are equal only when both the first things match and both the second things match, in that exact order.
So (Ravi, 15) equals (Ravi, 15), but it does not equal (15, Ravi) — even though both contain the same two items. The order matters.
The Precise Statement
(a,b)=(c,d)⟺a=c and b=d
Read this as: "The ordered pair (a, b) equals the ordered pair (c, d) if and only if a equals c and b equals d."
Two conditions must hold simultaneously:
- The first components are equal: a=c
- The second components are equal: b=d
If either condition fails, the pairs are different.
Why This Matters
This definition is the foundation for everything that uses ordered pairs — coordinates in the plane, relations, functions, and even complex numbers. When you plot the point (3,5) on a graph, you are implicitly using this rule: (3,5) is a different point from (5,3) because the first coordinates differ.
A common mistake is to think (a,b)=(b,a) just because the same two objects appear. That is false unless a=b. For example, (2,3)=(3,2).
Quick Check
Which of these are true?
- (4,7)=(4,7) → True (both components match)
- (4,7)=(7,4) → False (first components differ: 4=7)
- (x,5)=(3,5) → True only if x=3
- (p,q)=(q,p) → True only if p=q
The last one surprises many students. If p=q, then the pair becomes (p,p) and swapping gives the same thing. But if p=q, they are different.
One More Layer: Why "Ordered"?
Compare with a set {a,b}. In a set, order doesn't matter: {2,3}={3,2}. An ordered pair is fundamentally different — it preserves position. That's why we use parentheses ( ) instead of curly braces { }.
To remember: Parentheses = Position matters. Curly braces = Collection, order ignored.
So the equality rule for ordered pairs is simple, but it's the precise tool that lets us talk about coordinates, vectors, and relations without ambiguity.
The equality condition for ordered pairs is introduced right at the start of the NCERT Class 11 Mathematics chapter on Relations and Functions, and "ordered pair equality definition and examples" is a commonly searched foundational topic for CBSE board preparation. This precise rule underlies coordinate geometry and every later definition of a relation or function, making it a quick but frequently tested basic in "relations and functions important questions".
Concept: Ordered Pair Equality — two ordered pairs are equal iff their corresponding components are equal.
Step 1: Equate the first components:
3x+1=35
Step 2: Solve for x:
3x=35−1=35−33=32
x=2
Step 3: Equate the second components:
y−32=31
Step 4: Solve for y:
y=31+32=1
The values are x=2 and y=1, i.e. x=2, y=1.
Ordered pairs are equal only when their corresponding components are equal. Equating the x-coordinates gives x=2, and equating the y-coordinates gives y=1.
The idea is simple: an ordered pair is a pair of numbers where order matters.
So (a,b)=(c,d) means a=c and b=d — both must hold at the same time.
This is called the equality of ordered pairs, and it’s the only rule we need here.
We have:
(3x+1, y−32)=(35, 31)
Let’s break it down.
- Equate the first components (the x-coordinates):
3x+1=35
Subtract 1 from both sides. Write 1 as 33 to keep fractions consistent:
3x=35−33=32
Multiply both sides by 3:
x=2
- Equate the second components (the y-coordinates):
y−32=31
Add 32 to both sides:
y=31+32=33=1
A common mistake is to forget that both equalities must hold. Some students solve only one equation and assume the other automatically works — but here each coordinate gives a separate condition. Always check both.
When fractions look messy, rewrite whole numbers as fractions with the same denominator. Here 1=33 made the subtraction clean.
The values are x=2 and y=1.
Showing the 12 most recent of 15 on this concept.
- CBSE 2026Set ANNUAL1 markMCQQ.If (3x+1,y−32)=(35,31) then the value of x is(a) 1(b) 2(c) 3(d) None of these
›Reveal solutionSolution
Two ordered pairs are equal only if their corresponding coordinates are equal; equate the first coordinates and solve for x.
Two ordered pairs (a,b)=(c,d) are equal if and only if a=c and b=d. Here (3x+1, y−32)=(35, 31), so equating first coordinates:
3x+1=35
3x=35−1=32
x=2
(Equating second coordinates similarly gives y−32=31⟹y=1, though only x is asked.)
✓Final answer(b) 2.
- CBSE 2026Set ANNUAL1 markQ.Fill in the blank: If (x+1,y−2)=(3,1), then the value of y is ______.
›Reveal solutionSolution
Ordered pairs (x1,y1)=(x2,y2) iff x1=x2 and y1=y2; matching components gives the value of y.
Given (x+1,y−2)=(3,1).
Equating the first components: x+1=3⇒x=2.
Equating the second components: y−2=1⇒y=3.
✓Final answery=3.
- CBSE 2025Set ANNUAL1 markMCQQ.(x−2,11)=(5,11)⇒x=(a) 5(b) 7(c) 9(d) 11
›Reveal solutionSolution
x=7, found by equating the first components of the two equal ordered pairs.
Two ordered pairs (a,b) and (c,d) are equal if and only if a=c and b=d.
Given (x−2,11)=(5,11): the second components already match (11=11). Equating the first components: x−2=5⇒x=7.
✓Final answerThe correct option is (b) 7.
- CBSE 2025Set ANNUAL1 markMCQQ.Find a and b when (a−2b,13)=(7,2a−3b).(a) a=4,b=1(b) a=5,b=2(c) a=5,b=−1(d) a=6,b=7
›Reveal solutionSolution
Two ordered pairs are equal only when their corresponding entries are equal. Setting up and solving the resulting linear system gives a=5, b=−1.
Since (a−2b,13)=(7,2a−3b), equate the corresponding components:
a−2b=7...(1)
13=2a−3b...(2)
From (1): a=7+2b.
Substitute into (2):
13=2(7+2b)−3b=14+4b−3b=14+b
b=13−14=−1
Then a=7+2(−1)=7−2=5.
Check: a−2b=5−2(−1)=5+2=7 correct; 2a−3b=10−(−3)=10+3=13 correct.
✓Final answer(c) a=5,b=−1
- CBSE 2024Set ANNUAL1 markMCQQ.If (3x+1, y−32)=(35,31), then the values of x and y are(a) x=2, y=1(b) x=1, y=2(c) x=−1, y=−3(d) None of these
›Reveal solutionSolution
Equate the first components and the second components of the two ordered pairs separately, then solve each simple equation.
Two ordered pairs are equal iff their first components are equal AND their second components are equal. We are given:
(3x+1, y−32)=(35,31)
First components: 3x+1=35
3x=35−1=35−3=32
x=2
Second components: y−32=31
y=31+32=33=1
So x=2 and y=1.
✓Final answer(a) x=2, y=1.
- CBSE 2024Set ANNUAL1 markMCQQ.Assertion (A): If (4x + 3, y) = (3x + 5, -2), then x = 2 and y = -2 Reason (R): If A = {-1, 3, 4}, then A × A is {(-1, -1), (-1, 3), (-1, 4), (3, -1), (4, -1), (3, 4)}(a) (A) is true, (R) is true; (R) is correct explanation of (A)(b) (A) is true, (R) is true; (R) is not a correct explanation of (A)(c) (A) is true, (R) is false(d) (A) is false, (R) is true
›Reveal solutionSolution
(A) is verified true by solving the equal-ordered-pair equations; (R) is false because it lists only 6 of the 9 elements of A×A.
Checking Assertion (A): Two ordered pairs are equal iff corresponding components are equal.
(4x+3,y)=(3x+5,−2) gives:
4x+3=3x+5⇒x=2, and y=−2.
So x=2,y=−2 — Assertion (A) is true.
Checking Reason (R): For A={−1,3,4}, A×A should contain all 3×3=9 ordered pairs:
(−1,−1),(−1,3),(−1,4),(3,−1),(3,3),(3,4),(4,−1),(4,3),(4,4).
The reason statement lists only 6 pairs and omits (3,3),(4,3),(4,4) — so as stated, A×A is described incompletely, making Reason (R) false.
So (A) is true, (R) is false.
✓Final answer(A) is true, (R) is false — option (c).
- CBSE 2023Set ANNUAL1 markQ.If (3x+1, y−32)=(35,31), find the values of x and y.
›Reveal solutionSolution
x=2, y=1.
By equality of ordered pairs, (3x+1, y−32)=(35,31) means:
3x+1=35andy−32=31.
From the first: 3x=35−1=32⇒x=2.
From the second: y=31+32=1.
✓Final answerx=2, y=1.
- CBSE 2023Set ANNUAL1 markMCQQ.If (3x+1, y−32)=(35, 31) then value of x and y is(a) x=2, y=1(b) x=1, y=1(c) x=1, y=1(d) x=2, y=2
›Reveal solutionSolution
Equating components gives x=2, y=1; option (a).
By equality of ordered pairs (NCERT Class 11 Relations and Functions):
3x+1=35⇒3x=32⇒x=2,
y−32=31⇒y=1.
✓Final answer(a) x=2, y=1.
- CBSE 2022Set TERM11 markMCQQ.If (x+y,x−y)=(3,5) then x and y will be(a) x=3,y=1(b) x=1,y=3(c) x=4,y=−1(d) x=5,y=2
›Reveal solutionSolution
Two ordered pairs are equal exactly when their corresponding components are equal, giving a linear system to solve.
From (x+y, x−y)=(3,5): x+y=3 ...(i), and x−y=5 ...(ii). Adding (i) and (ii): 2x=8⇒x=4. Substituting into (i): 4+y=3⇒y=−1.
✓Final answer(c) x=4, y=−1.
- CBSE 2022Set ANNUAL1 markQ.If (x - 2) + (y + 1)i = 3 + 4i, then the value of x and y are ............ and ............ .
›Reveal solutionSolution
Comparing real and imaginary parts directly gives x=5, y=3.
(x−2)+(y+1)i=3+4i
Two complex numbers are equal only when their real parts are equal AND their imaginary parts are equal.
Real parts: x−2=3⇒x=5
Imaginary parts: y+1=4⇒y=3
✓Final answerx=5, y=3.
- CBSE 2021Set ANNUAL1 markQ.If 4x + i(3x − y) = 3 − 6i, then the value of x and y are ............., ............. respectively.
›Reveal solutionSolution
Matching real and imaginary parts gives x=3/4 and y=33/4.
Two complex numbers are equal only if their real parts match and their imaginary parts match.
4x+i(3x−y)=3−6i
Real parts: 4x=3⇒x=43
Imaginary parts: 3x−y=−6⇒y=3x+6=3(43)+6=49+424=433
✓Final answerx=43, y=433.
- CBSE 2020Set ANNUAL1 markMCQQ.If (x+y,x−y)=(3,5) then x and y will be:(a) x=3,y=1(b) x=1,y=3(c) x=4,y=−1(d) x=5,y=2
›Reveal solutionSolution
Two ordered pairs are equal exactly when their corresponding components match, giving two linear equations to solve together.
(x+y,x−y)=(3,5) means:
x+y=3...(i)
x−y=5...(ii)
Add (i) and (ii): 2x=8⇒x=4.
Substitute back into (i): 4+y=3⇒y=−1.
Check: x−y=4−(−1)=5 ✓.
✓Final answer(c) x=4,y=−1
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