Question

Solve by using substitution method. $3x+4y=10$ & $2x-2y=2$

• A. $x=2,y=1$
• B. $x=-1,y=-2$
• C. $x=1,y=0$
• D. $x=-2,y=3$

Answer 1

The correct option is A $x=2,y=1$

$3x+4y=10.....\left(1\right)$

$2x-2y=2.....\left(2\right)$

equation $\left(2\right)$ can be written as

$\Rightarrow x-y=1$

$\Rightarrow x=y+1.....\left(3\right)$

substitute $x$ value in equation $\left(2\right)$

$\Rightarrow 3x+4y=10$

$\Rightarrow 3(y+1)+4y=10$

$\Rightarrow 3y+3+4y=10$

$\Rightarrow 7y=7$

$\Rightarrow y=1$

then, substitute $y$ value in equation $\left(3\right)$

$\Rightarrow x=y+1=1+1=2$

$\therefore x=2,y=1$