## kcbrosell Group Title find an equation for the line with the given properties Question: Perpendicular to the line x − 2y = −5; containing the point (0, 4) 2 years ago 2 years ago

1. myininaya Group Title

so put that equation in this form: y=mx+b

2. myininaya Group Title

so we can find the slope of the perpendicular line after we do that

3. myininaya Group Title

Do you need help putting in that form?

4. MrYantho Group Title

1. Convert equation to y=mx+b, to find slope 2. Our second slope is the negative reciprocal of the given line's slope 3. Substitute the new slope, and the values of x and y into y=mx+b to solve for b (the y-int)

5. kcbrosell Group Title

I am not understanding

6. myininaya Group Title

Do you know how to write the equation given in this form: y=mx+b?

7. kcbrosell Group Title

no i do not

8. myininaya Group Title

You are just trying to solve for y: $x-2y=-5$ $\text{ add } 2y \text{ on both sides }$ $x-2y+2y=-5+2y$ $x=-5+2y$ Now add 5 on both sides $x+5=2y$ Now divide both sides by 2 $\frac{x+5}{2}=y =>y=\frac{x}{2}+\frac{5}{2} =>\frac{1}{2}x+\frac{5}{2}$ so what is the slope here?

9. kcbrosell Group Title

1/5=5 & 2/2=1, is that right

10. myininaya Group Title

y=mx+b where is m is slope so what is in front of x up there? 1/2 right? so what is the slope of a perpendicular line to this one? in other words what satisfies this equation 1/2 * ? = -1

11. kcbrosell Group Title

-1/2

12. myininaya Group Title

close -2 would be the slope of the perpendicular line

13. myininaya Group Title

so we have all lines are in this form y=mx+b => this line has this form: y=-2x+b

14. myininaya Group Title

now we know a point on the line (0,4)

15. myininaya Group Title

where x=0 and y=4 so we have enough info to find b replace x with 0 and y with 4 4=-2(0)+b how do you solve this for b?

16. kcbrosell Group Title

wouldnt you multiply each side by -4

17. myininaya Group Title

4=0+b since -2(0)=0 4=b since 0+b=b

18. myininaya Group Title

so the equation us y=-2x+4