189k views
5 votes
How to solve 3x+y=4 2x+y=5

1 Answer

1 vote
You can in this case simple subtract one equation from the other to eliminate the y variable...

(3x+y=4)-(2x+y=5)

3x-2x+y-y=4-5

x=-1, now you can substitute this value of x into either of the original equation to find the value of y...

3x+y=4 becomes

3(-1)+y=4

-3+y=4 add 3 to both sides

y=7

So the solution to the system of equations, where graphically the two lines intersect, is the point:

(-1, 7)
User Afraz Ali
by
7.9k points

No related questions found