Question

Evaluate 2(a² + b²), given that (a + b)² = = 144 and 4ab=18.

Answer 1

8 and -16

Explanation:

Let’s take the square root of both sides.

We get |a+b|=12

then replace 4 with “a”,

→ |4+b|=12

Now there are two possibilities for “b”.

→ 4+b=12

or 4+b=−12

→ We get b = 8 from the first one and we get -16 from the second one,

So the answers are 8 and -16 .