A rock is tossed into a lake and creates a ripple with a radius that increases at a rate of 20 cm/sec. The radius of the ripple can be expressed as the function R(t) = 20t, where t represents time in seconds. The area of the circle made by ripple can be expressed as
the function A(n) = Ter2, where r represents the radius in centimeters.
Which function can be used to determine the area of the ripple as a function of time?

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.