Here's the question you clicked on:
1honey
write an equation of the line containing the given point and perpendicular to the given line (7,9);2x+y=3
Do you know how perpendicular lines are related to eachother?
It has to do with their slopes.
that i don't understand how
I will tell you. Their slops are negative reciprocals of eachother. So if line 1 has a slope \(\frac{a}{b}\) then a perpendicular line 2 would have a slope of \(\frac{-b}{a}\)
So what is the slope of the line you've been given?