Question

For the equation 5x + 8y = 50, if y = 10, the value of x is
(a) 6
(b) −6
(c) 12
(d) −12

Answer 1

(b) −6
Given equation: $5x+8y=50$
If $y=10$, then
$5x+80=50$
⇒ $5x=-30$.
⇒ $x=-\frac{30}{5}=-6$
Hence, $x=-6$.