Once a commercial plane reaches the desired altitude, the pilot often travels at a cruising speed. on average, the cruising speed is 570 miles/hours. if a plane travels at this cruising speed for 7 hours, how far does the plane travels while cruising at this speed.

$6.42

step-by-step explanation:

hello from mrbilldoesmath!

answer:   x (x+6)^2, choice b

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb