The area of the patio is A=B·H. So substitute 4x+1 as the base and 2x-3 as the height to end up with (4x+1) (2x-3) use FOIL (bc the numbers are binomials) to simplify the equation (first, outer, inner, last) and multiply it together. Then combine like terms for the answer. The second one is the same. (7x-4) (8x+5)
