Find the equation of the line that passes through the point (-8,15) and is perpendicular to the equation below.

y = -4/5x + 5

A. y = -5/4x + 5
B. y = -4/5x - 7
C. y = -4/5x + 23
D. y = 5/4x + 25
Please help asap!

Respuesta :

Answer:

[tex]y = \frac{5}{4} x + 25[/tex]

Step-by-step explanation:

We were told that the equation of the line we are looking for is perpendicular to

[tex]y = - \frac{4}{5} x + 5[/tex]

We know that the gradient of perpendicular lines when multiplied is equal to -1, therefore

[tex] line \: .1 \times \: line \: .2 = - 1 \\ \\ \frac{4}{5} \times line \: .2 = - 1 \\ \\ line \: .2 = \frac{ - 1}{ \frac{4}{5} } [/tex]

[tex]line\: .2 = \frac{5}{4} \: \: \: \: y = 15 \: \: \: \: x = - 8 \\ \\ y = mx + c \\ \\15 = ( \frac{5}{4} ) - 8 + c \\ \\ 15 = - 10 + c \\ 15 + 10 = c[/tex]

[tex]25 = c \\ \\ therefore \: the \: equation \: of \: the \: line \: is \: \\ \\ y = \frac{5}{4} x + 25[/tex]