# How do you find a standard form equation for the line with (8, -2) and perpendicular to the line whose equation is x-5y-7=0?

##### 1 Answer

#### Explanation:

the basic equation of a straight line with known gradient

we are given a line perpendicular to the required line so we use the fact that if the gradient of the required line is

that is the product of the gradients of perpendicular lines is

so we use the line given to find the gradient

rearrange to the form

this is the perpendicular gradient

so

we also have

becomes

If the reader compares this with the original lines

a pattern may be seen .