Since there is a flat membership fee of $18, the y intercept is 18. And since there is a $3 fee per number of video games rented, n, the slope or rate of change of the linear equation is 3. The slope-intercept form of a line is:
f(x)=mx+b, where m=slope and b=y-intercept so in terms of n, games rented, the cost, f(n) is:
f(n)=3n+18
3 people x 8 hours is 24 hours / 5 people = 4 hours and 48 minutes
It would take 21 months for her to have exactly 1250
So since 8+12 is in parenthesis, you do that first. 8+12= 20, so then you multiply that by 4 and get 80!