This trend line shows a general pattern, and since we are with biological samples this trend line will not always be true. The outliers could be from either a genetic difference or an environmental difference that occured in the persons life.
Answer:
you have a fixed rate of $25, meaning you get a haircut, it's $25
ANY other service is an extra $15
So, let's make the equation...
y=15x+25
Now, to just get a haircut it's $25.
But, let's say you get a haircut+shampoo
It'd be..
y=15(1)+25
y=$40
Another one..
You get a haircut+shampoo+highlight
y=15(3)+25
y=$70
Answer:
5x+4y=85-
Slope = -2.500/2.000 = -1.250
x-intercept = 85/5 = 17
y-intercept = 85/4 = 21.25000
2x+3y=41-
Slope = -1.333/2.000 = -0.667
x-intercept = 41/2 = 20.50000
y-intercept = 41/3 = 13.66667
He would use 9 bills, and 5 coins. (fours $10, one $5, four $1. three quarters, one dime, and one penny). I calculated it all to make sure the total came out as 49.86