Acme phone company charges $21 a month plus 0.05 a minute .belltone phone charges $15 a month plus 0.11 a minute. write and solve an equation to determine how many minutes a month you must use for cost of using either company to be equal

it is true

step-by-step explanation:

all the combinations add up i used   calculator

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb