Victor borrow $21.50 from his mother to go to the builders a week later he paid her $21 and 50 back how much does he still own her

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

For the feasibility region shown below find the maximum value of the function p=3x+2y

Awindow has the shape of a rectangle with a semi circle at the top. find the approximate area of the window using the dimensions shown. 4ft by 8ft