Your answer would have to be 69with the remainder of 1
(open the picture for the shown work :) )
(x-8)(x+5)
First thing you do is put the X's into the parentheticals because it is x^2 meaning there are 2 factors with x's. Then, you wonder what factors of -40 could add to get -3. In this case, they are -8 and 5. -8 times 5 is -40 and -8 +5 is -3. Then, you just add -8 and 5 beside the x's in the parentheticals.
Sides:6.7,9.3,9.5
Tell me if that helps