Question

How do you solve `X^2 + 100 = 20X`?

Answer 1

First we get everything on the same side by subtracting `20x` on both sides.

Explanation:

`x^2-20x+100=0->`

Then we factor `100` into two factors that add up to `-20`,
those can only be `-10and-10`, so the whole left part can be factored:

`(x-10)(x-10)=0->x-10=0->x=10`