The answer is K= 7 because
-5-7=-12
9.50 + (2.20)r
For example if he fixed 3 watches
9.50 + (2.20)3
We plug in 3 for r and he makes 6.60 extra.
Its simple (n-12) because n is the variable and since it says fewer, then that means less than, which is subtracted by the number given which would be 12. Hope this helps! XD
