2 cm = 5 feet
1 cm = 2.5 feet
9 cm = 9 * 2.5 = 22.5 feet by
4 cm = 4 * 2.5 = 10.0 feet
Answer:
314 m²
Step-by-step explanation:
the surface area of a sphere (As) is
As = 4×pi×r²
our radius r (half of the diameter) here is 5m.
As = 4×3.14×5² = 4×3.14×25 = 100×3.14 = 314 m²
X*y=72
x = 5y-2
x=72/y
72/y=5y-2
72=5y^2-2y
5y^2 -2y - 72 = 0
(5y+18)(y-4)=0
y = -18/5 discard
or y = 4
4x=72
x=18
(18,4)