Since E is the midpoint, DE and EF are the same length.
Set the equation DE and EF equal to each other and solve for x.
2x + 4 = 3x - 1
x = 5
Then plug in 5 to find the length.
DE = 2(5) + 4 = 14
EF = 3(5) - 1 = 14
DF = DE + EF = 28
Answer:
x=6
Step-by-step explanation:
5x - 8 = 3x + 4
+8 +8
5x=3x+12
-3x -3x
2x=+12
/2 /2
x=6
I cannot see your picture, but if the plane cutting the cylinder is indeed perpendicular to the cylinder's base, then the cross section must be square or rectangular. Going by the shape of most cylinders, I would guess that it is rectangular.
S1 = 72
S2 = 12 = 72*(1/6)
S3 = 2 = 72*(1/6)^2
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S15 = 72*(1/6)^14 = 9.18*10^(-10)
