The first step would be :
E) 3x + (2x + 4) = -7
Seems to be an even function.
Angles in a triangle total 180°
180=128+5x+10+9x
180-128-10=5x+9x
42=14x
x=3
X=32
All triangles add up to 180 degrees so if the right angle is 90 degrees then you have 90 degrees left. Next, you take the 2x and x-6 and plug them into the equation 3x-6=90. Once you solve that you get x=32.
Answer:
The answer is 527.5km^3 .
Step-by-step explanation:
The formula for cylinders is πr2h. (pie times twice the height)
3.14(12)(2)(7) = 527.52