7. A water through of length 1 m has a triangular cross-section in the shape of an equilateral triangle of side 60 cm. Water is filled to the through at a rate of 50/3 ems. Find the rate
of increase of the depth of the water in the through when it has been filled for 10 minutes.
[12 marks]

answer: group b.

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

d is ur answer hopes this i dont really know how to explain it to u.