You just need to plug the values: you have to multiply
and
, and then divide the result by -3.
So, if
, we have 
Which means that 
And the final answer is 
Answer:
13
Step-by-step explanation:
If he reads 119 pgs in 7 days that mean 119/7 = 17 he reads 17 pgs per day
next 340-119 = 221 then 221/17= 13