Use substitution to determine the solution of the system of equations. y=-2x - 7
2y - x= 1

A. (-1, 0)
B. (21/2, -28)
C. (-6, -5/2)
D. (-3, -1)

The triangles are similar. what is the value of x? show your work.

What is the quadric regression equation that fits these data

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.