Question

Write the equation of the line passing through the points (-5,8) and (5,4)

Answer 1

The point slope formula:

We have:

`(-5,\ 8)\to x_1=-5,\ y_1=8\\(5,\ 4)\to x_2=5,\ y_2=4`

Substitute:

`m=(4-8)/(5-(-5))=(-4)/(10)=-0.4\\\\y-8=-0.4(x-(-5))\\\\y-8=-0.4(x+5)\ /\text{point slope form}/\\\\y-8=-0.4x-2\ \ \ |+8\\\\y=-0.4x+6\ /\text{slope intercept form}/\\\\y=-0.4x+6\ \ \ \ |+0.4x\\\\0.4x+y=6\ \ \ |\cdot5\\\\2x+5y=30\ /\text{standard form}/`