Alright, lets get started.
I hope, the dimensions of rectange are asked in this question.
Suppose the width of rectangle = x in
Given that length of the rectangle is 3 in longer than the width.
It means length of the rectangle = (x+3) in
Now, the area of the rectangle = lenght * width
area of the rectangle = [tex] x * (x+3) [/tex]
area of the rectangle =[tex] x^2+3x [/tex]
The area of a rectangle is 70 in square (given in question)
Equalling both areas
[tex] x^2 + 3x = 70 [/tex]
Subtracting 70 in both sides
[tex] x^2 + 3x - 70 = 70 - 70 [/tex]
[tex] x^2 + 3x - 70 = 0 [/tex]
Factoring
[tex] (x-7)(x+10) = 0 [/tex]
It will give two values of x
x = -10 (which is not possible because length could not be negative)
x = 7
Means width [tex] = 7 in [/tex]
length [tex] = 7 + 3 = 10 in [/tex]
Means the dimensions of rectangle are 7 in and 10 in. : Answer
Hope it will help :)