Answer:
a is 2x+2x and 4x
b is 6(7y-4) and 6*7y-6*4
The volume of a cylinder is given by the multiplication of the area of the base by the height of the cylinder. π×r²(area of the base) × h (height of the cylinder) ⇔

×

cm²×35cm=12127.5cm³
(r is half of the diameter. Because we are doing the square of r, the cm also are squared.)
Rounding to the nearest tenth is to round the result so that it maintains a number after the point - the result is 12127.5cm³
Step-by-step explanation:
the answer is 42 because 2 times the 21 equals 42
B because of the corresponding angles therom