20 because 16 is greater than 15 and we round the number up.
(3x - 8)(3x + 8) is 3.) 9x^2 - 64
(x + 6)^2 is 4.) x^2 + 12x + 36
(3x - 2)(x + 5) is 1.) 3x^2 + 13x - 10
5x(x - 1)(x + 7) is 2.) 5x^3 + 30x^2 - 35x
(x - 8)(x + 7) is 5.) x^2 - 10x + 16
I hope this helps!
The perimeter should be about 66
the first answer is 93000000 and the second answer is 240000
