Question

solve using elimination.
10x + 10y = -10
-9x - 10y = 19
(□, □)

Explanation:

Step1: Add the two equations

$$(10x + 10y) + (-9x - 10y) = -10 + 19$$
Simplify to eliminate $y$:
$$10x - 9x + 10y - 10y = 9$$
$$x = 9$$

Step2: Substitute $x=9$ into first equation

$$10(9) + 10y = -10$$
$$90 + 10y = -10$$

Step3: Solve for $y$

Subtract 90 from both sides:
$$10y = -10 - 90$$
$$10y = -100$$
Divide by 10:
$$y = \frac{-100}{10} = -10$$

Answer:

$(9, -10)$