Answer:
x² + 9x + 20
Explanation:
Area of a rectangle can be found by multiplying the base with height (or length with width).
A(r) = l x h.
Multiply. Plug in:
x + 5 for l
x + 4 for h
A(r) = (x +5) * (x + 4)
Use the FOIL method to solve. Multiply the first terms of both parenthesis, the outside terms, the inside terms, and then the last terms. Combine like terms:
A(r) = (x + 5) * (x + 4)
x * x = x²
x * 4 = 4x
5 * x = 5x
4 * 5 = 20
x² + 4x + 5x + 20
x² + (4x + 5x) + 20
x² + 9x + 20
x² + 9x + 20 is your answer.
~