Hey can u help pls

Question

Solve for x by using square roots:

x^2 + 28 = 8

The solution would be....

Answer 1

Hello, Lia,

x² + 28 = 8

Let's simplify:

x² = -20

We see that when x is squared, it winds up as a minus number. The only way that can happened is if we have an imaginary number. We'll use i, since i² = -1

Rewrite the equation using i² instad of -1, and by expressing 20 as the product of 4*5:

x² = i²*20

x² = i²*(4)*(5)

Now take the sqaure root of both sides:

x = i*2*5^1/2 [5^1/2 is the square root of 5)

and we also have

x = - i*2*5^1/2

Both are valid answers. Square both sides of either answer, and you'll wind up with the original simplified expression.

I hope this helps,

Bob

Answer 2

This equation has no REAL square roots.

x² = -20

x=±2i√5