Question

If √8-a + √5+a = 5, then √(8-a)(5+a) = ...
Please help me solve this.

Answer 1

Let's see if we can get to √(8-a)(5+a) from the following equation:

√(8-a) + √(5+a) = 5

Start by squaring both sides (whatever operation you do to one side of an equation you must do to the other side as well):

[√(8-a) + √(5+a)]^2 = 5^2

8 - a + 2√(8-a)(5+a) + 5 + a = 25

2√(8-a)(5+a) = 12

Divide both sides by 2:

√(8-a)(5+a) = 6 --->your answer

I hope this will help.

Answer 2

Helped alot! Thank you!