Answer:
x = 36
Step-by-step explanation:
Length of a rectangle, x+7
Width = 3
Area of the rectangle, A = 129 units²
The area of a rectangle is given by :
A = lb
So,
[tex](x+7)\times 3=129\\\\(x+7)=43\\\\x=43-7\\\\x=36[/tex]
So, the value of x is equal to 36.
