Question

1. \

$$\begin{cases} y - 2x = 5 \\\\ -2y + 7x = -4 \\end{cases}$$

substitution

Explanation:

Step1: Isolate y in first equation

$y = 2x + 5$

Step2: Substitute y into second equation

$-2(2x + 5) + 7x = -4$

Step3: Simplify and solve for x

$-4x - 10 + 7x = -4$
$3x - 10 = -4$
$3x = 6$
$x = 2$

Step4: Substitute x back to find y

$y = 2(2) + 5 = 9$

Answer:

$x=2$, $y=9$