Solve the system of equations by graphing.
y = 2x +1
y = 3
[Hint: Use a piece of scratch paper to graph.]
A. (3, 1)
B. (1, 3)
C. (3, 7)
D. (7, 3)

Question

Solve the system of equations by graphing.
y = 2x +1
y = 3 
[Hint: Use a piece of scratch paper to graph.]
            A.                    (3, 1)
            B.                    (1, 3)
            C.                    (3, 7)
            D.                    (7, 3)

anonymous · Answer

B. It's probably easier to use back substitution here. Since you know y=3, plug in 3 to the first equation as y, so 3=2x+1. then solve for x: 2=2x so x=1. That gives you the coordinate point (1,3). If you need to graph it, y=3 is a horizontal line through 3. y=2x+1 is a diagonal line with slope of 2 and a y-intercept of 1. you'll realize they do in fact intersect at (1,3)