Complete the equation of the line through (4,-8) and (8,5)

Question

asked May 16, 2020 71.3k views

2 Answers

Alex Stybaev · Answer 1 · 2020-05-23T06:00:53+0000

Answer:

The equation is
y=(13)/(4) x-24

Solution:

Here,
x_(1)=4 ; y_(1)=-8 ; x_(2)=8 ; y_(2)=5

We know the slope of an equation is given by y=m x+c

To find the value of m, we use the below given formula

m=(y_(2)-y_(1))/(x_(2)-x_(1))

Substituting the values we get,

$\mathrm{m}=(5-(-8))/(8-4)$

$\mathrm{m}=(5+8)/(4)$

$\therefore m=(13)/(4)$

Substituting the value of m in the slope intercept form we get,

y=(13)/(4) x+c

To find the The value of c, we substitute the value of x and y from any two given point. Let us take x = 4 and y = -8

$\Rightarrow-8=(13)/(4)(4)+\mathrm{c}$

$\Rightarrow-8=13+c$

$\Rightarrow-8-13=c$

$\Rightarrow-21=c$

Therefore, the slope intercept equation becomes
y=(13)/(4) x-21