+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
+129852 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
