7x+7y=-21 and 4x-2y=22 solve each system by substitution

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.

Aright triangle has an area of 21 m2. the dimensions of the triangle are increased by a scale factor of 4. what is the area of the new triangle