x² + 7 + 8 = 0
Add like terms.
x² + (7 + 8) = 0
Simplify.
x² + 15 = 0
We're simply just trying to find "x"
When solving for a variable, we need to get it isolated. That just means that we need to get it onto its' own side of the equal sign.
So, simply subtract 15 from both sides.
x² = -15
We have to subtract it so that it cancels out. If we had added 15 to both sides, then there would be an even larger number that is still on the same side as "x"
Find the square root of both x² & -15.
√x² = x
√(-15) = ±√(-15)
So, x = ±√(-15)
Therefore, this equation has no solutions.
~Hope I helped!~ :)