Question

find the solution of the system of equations.
-3x + 9y = -21
-3x + 8y = -18

Explanation:

Step1: Subtract eq2 from eq1

$$(-3x + 9y) - (-3x + 8y) = -21 - (-18)$$
Simplify: $y = -3$

Step2: Substitute $y=-3$ into eq1

$$-3x + 9(-3) = -21$$

Step3: Solve for x

$$-3x -27 = -21$$
$$-3x = -21 + 27$$
$$-3x = 6$$
$$x = \frac{6}{-3} = -2$$

Answer:

$x=-2$, $y=-3$