Question

Evaluate: $x+y=4;2x-5y=1$.

Answer 1

$x+y=4⟹2x+2y=8$ ............(1)

$2x-5y=1$ .......(2)

Subtracting equation 2 from 1, we get,

$7y=7⟹y=1$

Putting this value in equation 1, we get,

$x+1=4⟹x=3$

Hence, $x=3$ and $y=1$.