5(x-5)^4(x+4)
you raise x-5 to the 4th power because 5 has a multiplicity of 4
Check the picture below.
since we know that x = 3/7, we can then plug that on either of the twin legs, since it's an isosceles, and get the length of each leg, so say let's plug it in 5x + 16
![5x + 16\implies 5\left( \cfrac{3}{7} \right)+16\implies \cfrac{38}{7}+16\implies \cfrac{38+112}{7}\implies \cfrac{150}{7}\\\\[-0.35em]\rule{34em}{0.25pt}\\\\\stackrel{\textit{both legs}}{\cfrac{150}{7}+\cfrac{150}{7}}+\stackrel{\textit{base}}{6}\implies \cfrac{150+150+42}{7}\implies \cfrac{342}{7}\implies 48\frac{6}{7}\impliedby \textit{perimeter}](https://tex.z-dn.net/?f=5x%20%2B%2016%5Cimplies%205%5Cleft%28%20%5Ccfrac%7B3%7D%7B7%7D%20%5Cright%29%2B16%5Cimplies%20%5Ccfrac%7B38%7D%7B7%7D%2B16%5Cimplies%20%5Ccfrac%7B38%2B112%7D%7B7%7D%5Cimplies%20%5Ccfrac%7B150%7D%7B7%7D%5C%5C%5C%5C%5B-0.35em%5D%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%5Cstackrel%7B%5Ctextit%7Bboth%20legs%7D%7D%7B%5Ccfrac%7B150%7D%7B7%7D%2B%5Ccfrac%7B150%7D%7B7%7D%7D%2B%5Cstackrel%7B%5Ctextit%7Bbase%7D%7D%7B6%7D%5Cimplies%20%5Ccfrac%7B150%2B150%2B42%7D%7B7%7D%5Cimplies%20%5Ccfrac%7B342%7D%7B7%7D%5Cimplies%2048%5Cfrac%7B6%7D%7B7%7D%5Cimpliedby%20%5Ctextit%7Bperimeter%7D)
Perimeter of a square = 4L
4L = (8x+12)ft
L= (2x+3)ft
Well if 49 is the area, and you get area by multiplying one side by another side, and its a square so the numbers are going to be the same, so you would be multiplying two of the same numbers. And two of the same numbers that equal 49 is 7.