Step-by-step explanation:
if you could solve 3a and 3b, you can also solve 3c. it is the same principle.
x-intercepts means y = 0.
remember, a square root has always 2 results : a positive and a negative one.
3c
0 = -(x - 3)² + 25
(x - 3)² = 25
x - 3 = ±5
x1 = +5 + 3 = 8
x2 = -5 + 3 = -2
3a
0 = (x + 1)² - 4
4 = (x + 1)²
±2 = x + 1
x1 = +2 - 1 = 1
x2 = -2 - 1 = -3
3b
0 = (x + 2)² - 9
9 = (x + 2)²
±3 = x + 2
x1 = +3 - 2 = 1
x2 = -3 - 2 = -5
