Find the area of the circle. leave your answer in terms of pi
a)100pi cm^2
b)20pi cm^2
c)40pi cm^2
d)400pi cm^2

A) 100pi cm^2

Step-by-step explanation:

area of a circle: r^2pi

radius=1/2diameter

diameter=20 cm

radius=10cm

10^2pi cm

100pi cm^2

first car is x

second car is y

25x+30y=1550

x+y=55

Multiply the second equation by -25 for elimination method to cancel out x

-25x-25y=-1375

Add the two equations

5y=175

y=35

Plug this value into the second equation

x+35=55

x=20

Final answers:

First car=20 gallons

Second car=35 gallons