If y varies directly with x, and y=4 when x=1, what is x when y=8?

Hello can you me find all the products

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

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.