
First, turn
into an improper fraction with a denominator of 4, which matches
.

Now, just add the numerators.

Answer:
a cone with a base circumference of about 126 mm
Step-by-step explanation:
Rotating a triangle about a line results in a cone created by the rotation. This is because the segment at the bottom forms a circle, and the point at the top stays there; the three-dimensional figure with a circular base and a point at the top is a cone.
Since we rotate the segments about a line, this makes the length of the base the radius of the circle. This means the circumference would be
C = 2πr = 2(3.14)(20) = 125.6 ≈ 126 mm
She was not supposed to "undistribute" and separate 3x+1 she was supposed to subtract 1 from both sides