5/2
70 is the constant number that doesn’t change, but anytime you increase t you are raising it above 5/2. So every time you grow 5/2.
(6 + 5x)(7x + 3) = 42x + 18 + 35x^2 + 15x = 35x^2 + 57x + 18
I got 314 too, you have to use your formula a=pi(r2)
I'm assuming it is asking for surface area.
SA = 2(lw) + 2(hw) + 2(lh)
SA = 2(3*4) + 2(4*8) + 2(3*8)
SA = 2(12) + 2(32) + 2(24)
SA = 24 + 64 + 48
SA = 136 square feet
