Which of the following is a solution of the system x - 2y < 4 and y > – 2x – 5?

1. (1, - 4)
2. (-8,2)
3. (0,0)
4. (-3,0)

Answer B

Step-by-step explanation:

1.  (1, -4) is NOT a solution because (1) - 2(-4) < 4 is false.

2.  (-8, 2):  -8 - 2(2) < 4 is true, and in simplified form is -12 < 4 (true)  We must check whether this point (-8, 2) ALSO satisfies y > -2x - 5:

2 > -2(-8) - 5.  Yes, this is true, so the given point satisfies both inequalities in Answer B.

mia khalifa

step-by-step explanation:

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)