Need the answer noww pls

Which expression is equivalent to −16y+13 ? −16(−y+13) 16(−y+2) −16(y+2) 16(−y+13)

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)