Let a(t)a(t) be the area of a circle with radius r(t)r(t), at time tt in min. suppose the radius is changing at the rate of drdt=5drdt=5 ft/min. find the rate of change of the area at the moment in time when r=6r=6 ft

7x+8y=-18, 4x-9y=-3 solve the system of equations

Which statements are true? check all that apply. the line x = 0 is perpendicular to the line y = –3. all lines that are parallel to the y-axis are vertical lines. all lines that are perpendicular to the x-axis have a slope of 0. the equation of the line parallel to the x-axis that passes through the point (2, –6) is x = 2. the equation of the line perpendicular to the y-axis that passes through the point (–5, 1) is y = 1.

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account.write an expression to represent the total amount in his savings account.