00:01
Okay, for number 18, we're solving for x.
00:03
So in order to solve for x, first thing we need to do is get rid of the root that's isolated.
00:06
So we're going to square both sides.
00:08
Now it is very important that you use parentheses here, because on the left side, you're going to end up with 8 minus 2x like normal.
00:15
But now you're going to have 2x minus 2 times 2x minus 2, which is a foiling situation.
00:24
So we're going to foil out that right side.
00:27
We'll still have our 8 minus 2x on the left.
00:30
Left side for now, but we're going to end up getting 4x squared minus 8x plus 4 when it's all said and done.
00:40
We do need to move those two terms over to their proper spots and have this quadratic be set equal to 0.
00:47
So we're going to have 0 is equal to 4x squared minus 6x, negative 8x plus 2x, and then 4 minus 8 is minus 4.
00:57
Now since these are all even numbered co -oferred.
01:00
We're going to divide everything by two to make this easier.
01:03
So we're going to have 2x squared minus 3x minus 2.
01:08
So we do need a factor this.
01:09
I'm going to use my little box to help me keep organized.
01:13
I'm going to have 2x squared here, negative 2 here.
01:15
We're going to fill in these blanks here in a minute.
01:17
So whenever you have this lead coefficient, not 1, you're going to multiply first times last.
01:22
That's going to get you a 4...