how do I solve an equation by factoring?

Question

On my worksheet it says to factor each equation completely.  I do not fully understand how to do this.

Answer 1

X² - 4 is factored into the following expressions. (x + 2)(x - 2)

Note that the exponent is down to the first power. When you multiply the expressions back together, you can see how the middle term disappears.

x + 2

x - 2

x² + 2x - 2x - 4

All the terms have been multiplied back together.

x + 1

x - 4

x² + x - 4x - 4 = x² - 3x - 4

You can try multiplying a few simple expressions together to start with. Dividing them into their factors is just a matter of seeing how it works in reverse. The middle term always has the difference between the factors in an expression of the last numeral factor. You can find out that exchanging the plus and the minus above will result in the opposite operation for the middle term.

Hope this helps.