Respuesta :

Look, Jazly....

Let the width is w
and
the length is l

Then the perimeter is P = 2(l+w)

BUT
The width of the rectangle is 10 more than the length

That means: w=l+10

so we can write:

P = 2(l + w)
   = 2( l + l + 10)
   = 2(2l+10)
   = 4l + 20

and for P = 120

you want to solve for l:
 
120 = 4l + 20                            -20
120-20 = 4l + 20 -20
100 = 4l                                    / 4

l=25

and remember that:::  w = l+10
so: w = 25+10=35

w=35

I hope you got the idea



if you have 120 =2L +2(L+10)

distribute the 2nd part to get:

120 = 2L +2L +20

120 = 4L+20

100=4L

 L = 100/4 = 25

length = 25

 width = 25+10 = 35