Answer:
So the top right answer choice (x - 10)² = 80 has the same solution as x² - 20x + 20 = 0
Step-by-step explanation:
Let's solve your equation step-by-step.
x² − 20x + 20 = 0
For this equation: a = 1, b = -20, c = 20
1x² + −20x + 20 = 0
Step 1: Use quadratic formula with a = 1, b = -20, c = 20.
x = −b ± √b² − 4ac / 2a
x = −(−20) ± √(−20)² − 4(1)(20) / 2(1)
x = 20 ± √320 / 2
x = 10 + 4√5 or x = 10 − 4√5
Let's try the top right answer choice
(x−10)² = 80
Step 1: Simplify both sides of the equation.
x² − 20x + 100 = 80
Step 2: Subtract 80 from both sides.
x² − 20x + 100 − 80 = 80 − 80
x² − 20x + 20 = 0
For this equation: a = 1, b = -20, c = 20
1x² + −20x + 20 = 0
Step 3: Use quadratic formula with a = 1, b = -20, c = 20.
x = −b ± √b² − 4ac / 2a
x = −(−20) ± √(−20)² − 4(1)(20) / 2(1)
x = 20 ± √320 / 2
x = 10 + 4√5 or x = 10 − 4√5
