-10x + 3y = 34
y = -8x

Answer
Step 1: Simplify both sides of the equation.
−10x + 3(−8x) = 34
−10x + −24x = 34
(−10x + −24x) = 34 (Combine Like Terms)
−34x=34
Step 2: Divide both sides by -34.
x=−1
Answer:
x=−1
So the pair of coordinates for your answer is (-1, 8)