Answer: u=7
Step-by-step explanation:
-6= -2u+4(u-5)
-6= -2u+4u-20
-6= 2u-20
14= 2u
7=u
Step-by-step explanation:
We have xy = 28, x² + y² = 65 and x³ + y³ = 407.
Since (x + y)(x² - xy + y²) = x³ + y³,
x + y = (x³ + y³)/(x² + y² - xy)
= (407) / [(65) - (28)]
= 407 / 37
= 11.
Hence the sum of the numbers is 11.
So hmm notice the picture below
the pyramid itself, is really, just one regular hexagon, at the bottom
and 6 triangles, stacked up at each other at the edges
now, if you just get the area of the regular hexagon, and the 6 triangles, add them up, that'd be the total surface area of the pyramid then

now, for the triangles, well, area of a triangle is 1/2 bh, as you'd know, and you have both
I believe it 16/225 in fraction form