## Algebra 1: Common Core (15th Edition)

To check, take a value for x, such as x=4 ft. (I take this value because one side is going to be 10 ft, and multiplying with 10 is easy) Then, the dimensions of Kelly's plot are (10)$\times$(6), the area 60 f$t^{2}$. Substituting x=4 into the polynomial $x^{2}+8x+12$, which we arrived at in part (a), $(4)^{2}+8(4)+12=16+32+12=60,$ we get the same area, so it checks out well. Do the same for Roberto's plot. Take x=4, Dimensions: (10)$\times$(7), Area = 70. Polynomial ($x^{2}+9x+18$) value when x=4: $4^{2}+9(4)+18=16+36+18 = 70....$ so, this is also OK.