instead of using an = sign we use [tex] \leq [/tex] becuase its less than or equal to 100 dollars.
The equation of the line is y=10x+7
sub in 100 for y and the inequallity sign
10x+7[tex] \leq [/tex]100
solve so x is isolated
10x[tex] \leq [/tex]93
x[tex] \leq [/tex]9.3
technically the answer is 9 because you cant buy a fraction of a CD
