Question

What is the value of a, if a2 – 64 = 0 and a > 0? A) 0 B) 4 C) 8 D) 16

Answer 1

a2 - 64 = 0
a2 = 64
a = 32

32>0

Answer 2

Answer:

C) 8

Step-by-step explanation:

Let's solve for:

$a^2 -64=0\\\\a>0$

Add 64 to both sides:

$a^2-64+64=0+64\\\\a^2=64$

Take the square root of both sides

$\sqrt{a^2} = \sqrt{64} \\\\a=\pm 8$

Therefore, we got two solutions:

$a=8\\\\or\\\\a=-8$

However, since:

$a>0$

The only solution is:

$a=8$