The answer and the work

Step-by-step explanation:

Let's let represent the cost of tapes, and be the cost of CDs.

From the problem statement, we can create the following two equations:

To solve this system of equations, we can solve for in the second equation and substitute into the first equation to get the value of :

Substitution:

Now that we know the cost of the tapes, we can plug this value into either equation to get the cost of CDs:

or

Therefore, the cost of a tape is and the cost of a CD is .

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

step-by-step explanation: