Which system is equivalent to
{y=-2x2
y=x-2}

OPTION C: y = -2y² - 8y - 8

                    x = y + 2

Step-by-step explanation:

The given equations are:

From Equation (2), we get:

x = y + 2

Substituting this value of x in Equation (1), we get:

y = -2(y + 2)²

Expanding it in , we get:

y = -2{y² + 4y + 4}

⇒ y = - 2y² - 8y - 8

Therefore, OPTION C is the answer.

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)