Answer :
Answer:
5x + 4y = - 8
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Given
4x - 5y = 20 ( subtract 4x from both sides )
- 5y = - 4x + 20 ( divide all terms by - 5 )
y = [tex]\frac{4}{5}[/tex] x - 4 ← in slope- intercept form
with slope m = [tex]\frac{4}{5}[/tex]
Given a line with slope m then the slope of a line perpendicular to it is
[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex] = - [tex]\frac{1}{\frac{4}{5} }[/tex] = - [tex]\frac{5}{4}[/tex] , thus
y = - [tex]\frac{5}{4}[/tex] x + c ← is the partial equation
To find c substitute (- 4, 3) into the partial equation
3 = 5 + c ⇒ c = 3 - 5 = - 2
y = - [tex]\frac{5}{4}[/tex] x - 2 ← in slope- intercept form
Multiply through by 4
4y = - 5x - 8 ( add 5x to both sides )
5x + 4y = - 8 ← equation in standard form