What is the answer to this question?

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

$320 to $405

step by step explanation:

in one day he earns between $64 and $81

therefore if he works for 5 days, he will earn between 64 x 5 to 81 x 5

= $320 to $405

add 8+12 to get a simplified answer of 12r-20