## anonymous one year ago Which equation produces a line that is perpendicular to the line represented by the function below Y=2/5x+9 A)5x+2y=4 B) 2x-5y=8 C) 5x-2y=-3 D) 2x+5y=-7

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So, this one wants to be tricky. They give you slope intercept and you have to find it in standard. I will start out answering by asking you, Do you know the difference between slope intercept and standard?

@ItsStephanie ?

3. anonymous

Yes

How do you convert a standard problem to slope intercept?

5. anonymous

Well I know what they both look like but not how to convert

So if I tell you the slope of the perpendicular is going to be $$-\frac{ 5 }{ 2 }$$ what would be your choice?

7. anonymous

Between the two?

the first one

9. anonymous

Slope-intercept form

10. anonymous

The given equation is y = (2/5) x +9 Hence the perpendicular line will have the slope is $$-\dfrac{5}{2}$$ Then, the required line will have the equation : $$y = -\dfrac{5}{2}x +b$$ $$2y = -5x+2b\\2y+5x =2b$$ That means the right hand side must be an even number. You have 2 options whose the left hand side are the same $$2y+5x$$ But only one whose the right side is an even number. That is ....... ????