In 15 the perimeter of the figure is given. find the length of the indicated side
rectangle width = 3x-3 perimeter = 10x +6

Hello from MrBillDoesMath!

l = 2x + 6

Discussion:

From the attachment, where l = length, w = width, and P = perimeter

P =  2l + 2(3x-3)

The Question states that P = 10x + 6 also, so equating the last two items gives

2l + 2(3x-3) = 10x + 6                   => 2(3x-3) = 6x - 6

2l + (6x-6) = 10x + 6                     =>

2l + 6x - 6 = 10x + 6                     =>  subtract 6x from both sides

2l + (6x - 6x) -6 = (10x - 6x) + 6    => as 6x - 6x = 0 and 10x - 6x = 4x

2l -6 = 4x + 6                                => add 6 to both sides

2l =  4x + 6 + 6                              => 6 + 6 = 12

2l = 4x + 12                                   => divide both sides by 2

l = 2x + 6

Thank you,

MrB

start with a line segment pq that we will copy. mark a point r that will be one endpoint of the new line segment. set the compasses' point on the point p of the line segment to be copied. adjust the compasses' width to the point q. the compasses' width is now equal to the length of the line segment pq.

step-by-step explanation:

answer: what do you mean