If Joe gave 5 pics to site A. Site A would give him $0.75*5=$3.75
If Joe gave 5 pics to Site B. Site B would give him $0.25*5=$1.25
3.75-1.25=2.50
Site A gave him $2.50 more than Site B.
keeping in mind that parallel lines have exactly the same slope, let's check for the slope of the equation above

so we're really looking for the equation of a line whose slope is 1/2 and passes through (-4 , 1)

Answer:
-19
Step-by-step explanation: