What is RU?
A.20
B.30
C.12
D.15

a

Step-by-step explanation:

The segment  RT is a perpendicular bisector and means Δ RSU is isosceles, then the 2 legs are congruent, that is

RS = RU , substitute values

8x = 6x + 5 ( subtract 6x from both sides )

2x = 5 ( divide both sides by 2 )

x = 2.5

Thus

RU = 6x + 5 = 6(2.5) + 5 = 15 + 5 = 20 → a

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