Question

7. If x² + 4 = 29, then x² - 4 = ?
A. 5
B. √21
C. 21
D. 25
E. 33

Answer 1

21

Explanation:

So if x²+4=29 we need to find the value of x

ie. x²=29-4

x²=25

x=√25=±5

Plugging this into the equation it becomes

5²+4=29

now x²-4=5²-4=21