Answer:
a. -200
Step-by-step explanation:
Square root both sides:
x = +/- 200
x = -200, 200
x = -200
Answer:
b
Step-by-step explanation:
Given
x² = 400 ( take the square root of both sides )
x = ± [tex]\sqrt{400}[/tex] = ± 20
Thus x = - 20 is a solution of the equation → b