The width of a rectangle is 3x - 3. perimeter is 10x + 6. find the length of the rectangle.

2x+6

Step-by-step explanation:

The perimeter of a rectangle is given by adding up it's 4 side measurements.

Since it is a rectangle, not all sides will be equal all the time.  You do know however that opposite sides are equal.

So two sides will have the same measurement, u.

Another two sides will have the same measurement,v.

So you have the perimeter, P, can be found by doing u+u+v+v.

Simplifying gives:

P=2u+2v.

You are given the width is (3x-3).  Choose this to be u or v but not both.

Perimeter is given a (10x+6).

Let's plug this in:

(10x+6)=2(3x-3)+2v

We are solving for v.

First step: Distribute where you can:

10x+6=6x-6+2v

Now we want to isolate v.

So we will need to subtract (6v-6) on both sides:

 (10x+6)=2v

- (6x -6)

4x+12  =2v

The right hand side contains a factor of 2.

The left hand side does too since 4x+12 can be factored as 2(2x+6).

2(2x+6)=2v

This implies v is 2x+6.

Let's check our work.

We have two sides with measurement 2x+6:  (2x+6)+(2x+6)=4x+12

We have two sides with measurement 3x-3:   (3x-3)+(3x-3)=  6x-6

Let's add those sums to find the perimeter:                             10x+6

That is the intended perimeter.

it would be 6xy and -16xy.