the problem is that I have to find the length of x.

Question

Here's what they say:
Find the missing length, when the perimeter is 9x+11

then here are the length that are given on the shape: 2x+3 and 3x+1

How could I solve this?

Answer 1

Three sides: add them to get perimeter.

x + 2x+3 + 3x+1= 9x+11

solve for x.

Answer 2

But the problem is about adding and subtracting polynomials...

This is what I did...

2x+3+3x+1
=2x+3x+3+1
=5x+4

and

9x+11-5x+4
=9x-5x+11+4
=4x+15

but then, if I add both 5x+4+4x+15
=9x+19...

Answer 3

BobPursely gave this equation:

x + 2x+3 + 3x+1= 9x+11

If you only look at the left side, you'll get 6x + 4.

Your new equation should read:

6x + 4 = 9x + 11

Does that help?

Answer 4

im not sure?

Answer 5

Ok. From here, you need to solve for x. The easiest way to do that is to get x on one side of the equation. Do you know how to do that?

Answer 6

yes :)