What does it mean when it asks you find f(-3)

It means that you have to answer the equation which the answer is -4.

Explanation: We can substitute −3 for x and simplify:

f(x) = 2x+2

f(−3)= 2(−3) + 2

f(−3)= −6+2

f(−3)= −4

So f(−3)=−4.

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