Answer:
B
Step-by-step explanation:
The area of the Sandbox is given as x^2 + 3x
You are also given that the width of the sandbox is x
The question is, what is the length
Formula
Area = L * w Substitute the givens into the formula
x^2 + 3x = L * x Use the distributive property to put brackets on left.
(x^2 + 3x) = L*x Pull out the common factor on the left.
x(x + 3) = L * x Divide both sides by x
x(x + 3)/x = L*x/x
x + 3 = L
