Question

Solve the following sets of simultaneous equations.
$x+y=4;2x-5y=1$

Answer 1

Given

$x+y=4$

$x=4-y.........\left(1\right)$

$2x-5y=1$

Putting the value of $x$ from (1) in the above equation, we get

$2(4-y)-5y=1$

$8-2y-5y=1$

$8-7y=1$

$7y=8-1$

$7y=7$

$y=1$

Putting the value on $y$ in (1), we get

$x=4-y$

$x=4-1$

$x=3$

Therefore, $x=3$ and $y=1$