Answer:
x = -10, 10
Step-by-step explanation:
Step 1: Write out function
f(x) = 8x² - 800
Step 2: Set equal to 0
0 = 8x² - 800
Step 3: Add 800 on both sides
800 = 8x²
Step 4: Divide both sides by 8
x² = 100
Step 5: Take square root on both sides
x = ±10
Step 6: Arrange
-10 < 10
So x = -10, 10
