F(x) means "function of" and x represents the day number, example: day 6 would be f(6)=(20×6)+95
Converting feet to inches, 8*12=96 and 96*4=384. Next, 40*12=480. Since 384*x (if x represents the cost per inch of crown molding)=16*100=1600 cents due to that for every inch, we add x amount of money, we can find x to be 1600/384=800/192=400/96=200/48=100/24=50/12=25/6 by simply dividing both the numerator and denominator by 2 each time. Since we add x amount of money for every inch, and we have 480 inches, 480*x=480*25/6=2000 cents=2000/100=20 dollars is our answer
Just take the coordinates of both those red dots and use the slope formula: y2-y1 all divided by x2-x1. that should give you slope
