Ahard cover books cells for $16.50 the same title in paperback sells for $4.95 how many hard cover books must a dealer sell to take in as much money as he or she does for 30 paperback copies

the answer for hard cover books is 495 for 30 hard cover books

Step-by-step explanation:

ok so he pays $148.50 for 30 papaer back books but i don't really get tour question

i'm not sure i quite understand, could you provide more information?

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)