Elaine bought 11 feet 8 inches of fancy ribbon for $392. The spool was stained and some length of
the ribbon was soiled and not usable. She quickly
sold the remaining ribbon to George at a per-inch
price of 3/7 higher than she paid for it. Altogether,
she made a profit of $28. What percentage of the
ribbon was soiled?

answer are

step-by-step explanation:

30005

yes ok                                            

hello from mrbilldoesmath!

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

discussion:

in general, the factorization of a^3 + b^3 is

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

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

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

you,

mrb

(a + b) (a^2 - a b + b^2)

the answer is 8.64

step-by-step explanation: