Question

Solve the following equations by substitution method.

$x+3y=10;2x+y=5$

• A. $x=1,y=3$
• B. $x=2,y=3$
• C. $x=1,y=1$
• D. None of these

Answer 1

Answer: (A)

$x=1,y=3$

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

$2x+y=5$........$\left(2\right)$

$y=5-2x$......from $\left(2\right)$

putting in $\left(1\right)$, we get

$\Rightarrow x+3(5-2x)=10$

$\Rightarrow x+15-6x=10$

$\Rightarrow -5x=-5$

$\Rightarrow x=1$

$1+3y=10$

$y=3$