90+30x+30y. This is because the first day, 90 labels were printed, then you will use 30 times x to find how many minutes. This is the same for 30 times y. Youre trying to figure out how many minutes each machine printed for.
8 + 3 (4 - n )
n= 3
8 + 3( 4-3)
8 + 3 * 1
8 + 3 = 11
Area of a Circle = PI * radius^2
= 3.14 * 1.8^2
= 3.14 * 3.24
= 10.17 meters^2