1. A student determined that the ordered pair l(1,3)is a solution of the following system.

x+y=-2

5x+y=5

His reasoning was that the ordered pair satisfies the first equation x+y=-2, since 1+(-3)=-2. What went wrong?

2.Decide whether the given ordered pair is a solution of the given system. (-2,-4) : 3x+5y=-26

4x+2y=-16

Is the ordered pair a solution?

3.Determine whether the given ordered pair is a solution of the system of equations. Remember to use alphabetically ordered variables. (5,-8) : 4x=12-y

2x=50+5y

Is the ordered pair asolution?

4.The price perunit, p, and thedemand, x, for a particular material are related by the linear equation p=120-6/7x, while the supply is given by the linear equation p=6/7x. At what value of p does supply equaldemand?