Question

How do you find a standard form equation for the line with point (9, -9) and is parallel to the line 7x-9y+5 = 0?

Answer 1

`y=7/9x-16`

Explanation:

Rewrite the given equation as:

`y_1=7/9x_1+5/9`

The gradient being `+7/9` so any line parallel to this will have the same gradient.

Thus for the new line we have: `y_2=7/9x_2+c`.....................Equation(1)

Given that a point on this line is:`" "P_1->(x_2,y_2)=(9,-9)`

Thus by substituting `P_1` into Equation(1) we have:
`-9=7/(cancel(9))(cancel(9))+c`

`=>c=-9-7=-16`

Giving:`" "y_2=7/9x_2-16`