00:01
For this problem, it says that a rectangle has a length of 21 inches less than 5 times the width.
00:06
So the width is going to be x, and the length would be 5x minus 21, since it's 21 less, than 5 times the width.
00:19
Okay, the area is 5 ,390 find the length of the rectangle.
00:26
So what i'm going to do here is since the area of a rectangle is length times width.
00:32
I'm going to plug in the area, which is 5 ,390, and set that equal to the length times the width.
00:42
So x times 5x minus 21.
00:46
From here, i'm going to distribute, and i'm going to subtract the 5 ,390 to the other side.
01:08
From here, i'm going to try and factor this.
01:10
So i'm going to multiply 5 times 5 ,390, which gives me 26 ,000.
01:20
950.
01:22
I need two numbers that multiply to that and add to negative 21, which are negative 175 and positive 154.
01:36
So i'm going to go ahead and factor...