Please help please :)

For what values of b will f(x)= logbx be a decreasing function? (16 )

Use the elimination method to solve the system of equations -x+5y=-4 and 4x+3y=16

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).