Gsolve the equation, and check the solution. r plus 7 equals 9r+7=9 the solution set is startset nothing endset . (type an integer or a fraction.)

... r + 7 = 9

... r

Subtract 7 from both sides of the equation.

... r + 7 - 7 = 9 - 7

... r = 2 . . . . . . simplify

Expressed as a solution set, this may look like ...

... r ∈ {2}

You probably had no trouble solving this in 2nd grade when it was shown to you in the form ...

__ + 7 = 9

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk