Sheffield corporation sells sets of pots $14 and dishes $12 at local charity. On Labor Day weekend Sheffield’s total sales were $1080. People bought three times as many pots as dishes. How many of each did Sheffield’s sell?

Can someone me with my hwplz(only the circled ones)

To find the extreme values of a function f(x.y) on a curve x-x(t), y y(t), treat f as a function of the single variable t and use the chain rule to find where df/dt is zero. in any other single-variable case, the extreme values of f are then found among the values at the critical points (points where df/dt is zero or fails to exist), and endpoints of the parameter domain. find the absolute maximum and minimum values of the following function on the given curves. use the parametric equations x=2cos t, y 2 sin t functions: curves: i) the semicircle x4,y20 i) the quarter circle x2+y-4, x20, y20 b, g(x,y)=xy

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)