Question

1. $-2x - y = -9$

$5x - 2y = 18$

Explanation:

Step1: Eliminate y variable

Multiply first equation by -2:
$$-2(-2x - y) = -2(-9)$$
$$4x + 2y = 18$$

Step2: Add to second equation

Add new equation to $5x - 2y = 18$:
$$(4x + 2y) + (5x - 2y) = 18 + 18$$
$$9x = 36$$

Step3: Solve for x

Divide both sides by 9:
$$x = \frac{36}{9} = 4$$

Step4: Substitute x into first equation

Plug $x=4$ into $-2x - y = -9$:
$$-2(4) - y = -9$$
$$-8 - y = -9$$

Step5: Solve for y

Isolate y:
$$-y = -9 + 8$$
$$-y = -1$$
$$y = 1$$

Answer:

$x=4$, $y=1$