+0  
 
0
44
2
avatar+96 

Line $l_1$ represents the graph of $3x + 4y = -14$. Line $l_2$ passes through the point $(-5,7)$, and is perpendicular to line $l_1$. If line $l_2$ represents the graph of $y=mx +b$, then find $m+b$.

 

Thank you in advance

 Mar 22, 2021
 #1
avatar+117787 
+2

3x  +4y  =  -14

 

4y  = -3x   - 14

 

y  = -(3/4)x - 14/4

 

y=  -(3/4)x  -7/2

 

The slope of this line =  -3/4

 

The  slope ofthe perpendicular line =  4/3

 

So...using the  slope and point (-5, 7)    we have

 

y = (4/3) ( x - - 5)  +  7

 

y= (4/3)( x + 5)  + 7

 

y= (4/3)x  + 20/3  + 21/3

 

y= (4/3)x  + 41/3

 

m + b =   4/3  + 41/3  =  45/3  =  15

 

Here's a graph :  https://www.desmos.com/calculator/uxagghudww

 

cool cool cool

 Mar 22, 2021
 #2
avatar+96 
+1

That is correct! Thank you so much.

 

Can you help with my other question too please?

Immaguest  Mar 22, 2021
edited by Immaguest  Mar 22, 2021

20 Online Users

avatar
avatar
avatar
avatar
avatar