Which shows the algebraic representation of the phrase and its value when n = 4.2? “twenty-eight plus the product of five and a number” 28 minus 5 n; when n = 4.2 the value is 7 28 + 5 n; when n = 4.2 the value is 49 28 n minus 5; when n = 4.2 the value is 112.6 28 n + 5; when n = 4.2 the value is 122.6

hey! so 1 (25) out of 4 (100) is 25 so your answer is 25%. it's like quarters!

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