In the diagram below of triangle HIJ, K is the midpoint of H J and L is the midpoint of
IJ. If KL= -3.2 + 39, and
HI = 6x + 18, what is the measure of HI?

HI = 48 units

Step-by-step explanation:

By midpoint theorem,

"Line segment joining midpoints of two sides of a triangle measures the half of the third side of a triangle."

Since, KL is the segment joining midpoints of JH and JI,

-3x + 39 =

-3x + 39 = 3x + 9

6x = 30

x = 5

Therefore, HI =  6x + 18

                      = 6(5) + 18

                      = 30 + 18

                      = 48

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