Question

Solve by elimination:

3x - y = 17
2x + 5y + 1 = 10

Answer 1

3x - y = 17 . . . (i)
2x + 5y = -1 . . . (ii)

Multiplying equation (i) by 5 and solving it with equation (ii), we get
$2x+5y=-1\underset{–}{15x-5y=35}17x=34$
(Adding)

$\Rightarrow x=\frac{34}{17}=2$

Putting the value of x in (i), we have
$3\left(2\right)-y=7$

$\Rightarrow 6-y=7\Rightarrow -y=7-6$

$\Rightarrow y=-1$

$\therefore x=2,y=-1$