## EXOEXOEXO one year ago what is the equation of the line that passes through the points (3,4) and (-1,5)

1. dan815

slope of the line = $\frac{y2-y1}{x2-x1}$

2. dan815

let m be the slope of a line $m=\frac{y2-y1}{x2-x1}$ y=mx <--- is that line that goes through the origin you can displace that line by some y value and x so that its not going through the origin with that slope but its going through one of your points

3. dan815

|dw:1442638013903:dw|

4. EXOEXOEXO

you can move the line by having a y intercept with the same slope?

5. dan815

well thats an idea

6. dan815

so you're saying we should find this point |dw:1442638180453:dw|

7. dan815

lets say that value is b

8. dan815

y=mx+b shifts the y=mx by b units up as we are adding b to every value on the line now

9. dan815

|dw:1442638272009:dw|

10. dan815

having a line equation means your point satisfies the equation you have for your line

11. dan815

y=mx+b so when you plug in your point (3,4) oor when you plug in your point (-1,5) it satisfies the equation y=mx+b

12. dan815

so when you plug in 3,4 4=m*3+b when you plug in -1,5 5=m*-1+b

13. EXOEXOEXO

4=-3/4+b and 5=1/4+b?

find the slope by the formula y2-y1/x2-x1

5-4/-1-3=-1/4

now equation of the line- y-y1=m(x-x1) y-4=-1/4 (x-3)

4y+x=19