Question

Solve $x+3y=16,2x-y=4$ by using substitution method.

Answer 1

We have $x+3y=16$ ..... (1)

$2x-y=4$ ...... (2)

Equation (1) becomes, x = 16 - 3y ...... (3)

Substituting the above relation of $x$ in (2) and we got,

$\Rightarrow 2(16-3y)-y=4$

$\Rightarrow 32-6y-y=4$

$\Rightarrow -6y-y=4-32$

$\Rightarrow -7y=-28$

$\Rightarrow y=\frac{-28}{-7}=4$

Substituting $y=4$ in eq. (3) we got, $x=16-3\left(4\right)$

$=16-12=4$

$\therefore$ The solution is x = 4 and y = 4.