Question

-4x + y = 6\
-5x - y = 21

Explanation:

Step1: Add the two equations

$$(-4x + y) + (-5x - y) = 6 + 21$$
Simplify to eliminate $y$:
$$-9x = 27$$

Step2: Solve for $x$

$$x = \frac{27}{-9} = -3$$

Step3: Substitute $x=-3$ into first equation

$$-4(-3) + y = 6$$
Simplify the left side:
$$12 + y = 6$$

Step4: Solve for $y$

$$y = 6 - 12 = -6$$

Answer:

$x=-3$, $y=-6$