Answer:
Step-by-step explanation:
MX = XN
5r² + 2r + 52 = 4r² + 12r + 27
5r² - 4r² + 2r - 12r + 52 - 27 = 0
r² - 10r + 25 = 0
(r - 5)² = 0
r - 5 = 0
r = 5
4r² + 12r + 27
4•5² + 12•5 + 27
4•25 + 60 + 27
100 + 60 + 27
187
The Second one
I hope I helped you.
Just look at the perpendicular cross section, which would be an isosceles triangle. Split that in half vertically and you get a right triangle.
a) 1,000 + 0 + 40 + 9
b) 40,000 + 3,000 + 800 + 70 + 0
c) 8,000,000 + 100,000 + 5