Write the equation of the circle: center at (0,0), diameter 18

x^2+y^2=81

Step-by-step explanation:

the equation is

(x-h)^2+(y-k)^2=r^2

since the center is (0,0) you don't even put it in the equation

so all you will have is the x and the y

you leave in the square (^2)

you divide the diameter by 2 to get the radius

9

then you square the radius

81

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.