Chapter 3 · Question 5

Solve $2x+3y=11$ and $2x-y=3$ by elimination.

Answer Revealed

Direct Answer:

Subtract the second equation from the first:

(2x+3y)-(2x-y)=11-3

, so

4y=8

y=2

. Substitute in

2x-y=3

2x-2=3

, so

x=\frac52

Eliminate

x

by subtracting. You get

y=2

, then

x=2.5

The equations are

2x+3y=11

and

2x-y=3

. Since coefficients of

x

are equal, subtract the second from the first:

4y=8

, so

y=2

. Put

y=2

2x-y=3

2x-2=3

, so

2x=5

and

x=\frac52

Subtract the second equation from the first: $(2x+3y)-(2x-y)=11-3$ , so $4y=8$ , $y=2$ .
Use the NCERT formula or theorem carefully.
Write units and final conclusion where applicable.

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