## Littlebird one year ago Is this a system of equations? 4x-y=4 -4x+y=-4

1. ganeshie8

linear system of two dependent equations

2. Littlebird

How do I find out if it has a solution?

3. iGreen

Graph it or solve it

4. iGreen

Multiply -1 to the 2nd equation..what do you get?

5. anonymous

A system of equations is a collection of 2 or more equations with the same set of unknowns

6. Littlebird

In both equations, when solving for y,I got y=4x-4 Does that mean they have no solution, or one unique solution?

7. iGreen

$$\sf (-4x + y = -4) \cdot -1 = ~ \! ?$$

8. anonymous

wrong answer....do what igreen says...it will eventually make sense to you

9. Littlebird

4x-y=4

10. anonymous

oh..I see what you did LittleBird...you see that both equations are equal...they are the same. That means they are the same line......infinite solutions

11. Littlebird

I have another similar problem where the lines are parallel. Does that mean they have no solution?

12. anonymous

Little lesson.. (when finding out how many solutions a system of equations have) In y = mx + b form, the slope is in the m position and the y intercept is in the b position. (when comparing a system of equations).. If the slope and the y intercepts are equal, then it has infinite solutions if the slope is the same, but the y intercepts are different...parallel lines with no solutions. if the slopes and the y intercepts are different, then it has 1 solution

13. Littlebird

That is exactly what I needed to know! Thanks!

14. anonymous

anytime :)