SOLUTION: Problem- y = x+1 y = 2x-1 The question from my text book is: Solve each system of equations on the same set of axes.Tell whether the system is consistent or inconsi

Algebra ->  Graphs -> SOLUTION: Problem- y = x+1 y = 2x-1 The question from my text book is: Solve each system of equations on the same set of axes.Tell whether the system is consistent or inconsi      Log On


   

Question 123852: Problem- y = x+1
y = 2x-1
The question from my text book is: Solve each system of equations on the same set of axes.Tell whether the system is consistent or inconsistent and whether the equation are dependent or independent.
I'm trying to solve this by using the y=mx+b formula.Is this the correct formula to use?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
You already have the equations in slope-intercept form y=mx%2Bb, so you can tell the slope of each of the lines directly by examining the coefficient on the x terms. Since inconsistent systems are systems that are either parallel or the same line, inconsistent systems are systems that have the same slope. Here, the slopes are different. One is 1 and the other is 2. So you know the lines are not parallel, must intersect in a single point, and are therefore consistent.

graph%28400%2C400%2C-5%2C5%2C-5%2C5%2Cx%2B1%2C2x-1%29

y=x%2B1 multiplied by -2 is -2y=-2x-2. Add this to y=2x-1

-y=-3, y=3
3=x%2B1, so x=2. The two lines intersect at (2,3), which looks about right from the graph.