SOLUTION: Solve the system by graphing and then get an exact solution by using either substitution or elimination : 2x - y = -1 6x + 3y = 0

Algebra ->  Expressions-with-variables -> SOLUTION: Solve the system by graphing and then get an exact solution by using either substitution or elimination : 2x - y = -1 6x + 3y = 0      Log On


   

Question 64832This question is from textbook An Incremental Development
: Solve the system by graphing and then get an exact solution by using either substitution or elimination :
2x - y = -1
6x + 3y = 0 This question is from textbook An Incremental Development

Answer by rchill(405) About Me  (Show Source):
You can put this solution on YOUR website!
graph%28200%2C200%2C-3%2C3%2C-3%2C3%2C2x%2B1%2C-2x%29. From the graph, it appears the lines intersect at (-1/4, 1/2), but can't tell for certain. So you will need to solve by adding the two equations together or by substitution. Using the latter, the first equation becomes y=2x+1, so use that in the 2nd equation thusly: 6x+3(2x+1)=0, which simplifies to 6x+6x+3=0, which further reduces to 12x=-3, and finally x=-1%2F4. Using that value of x in the first equation, we get y=1%2F2.