Which of the following statements is a true proportion?
a.
18/32 = 27/48

b.
18/42 = 9/24

c.
18/42= 21/48

d.
18/42 = 118/142

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

If 25% of y is 30, what is 60% of y?