The radius is 7 what it is telling you is that you already did the square 4^2*3.14=49 pi.
5 x 5 x 5
Expanded just means writing it out as you would solve it. So solving a cube would be multiplying the number by itself 3 times
We can use the FOIL method to solve.
(5x + 3)(7x - 7)
(5x * 7x) + (5x * -7) + (3 * 7x) + (3 * -7)
35x - 35x + 21x - 21
0 + 0
0
Best of Luck!
