Take -5x + 3x = -2x
because there is a -3x and a 3x they cancel each other out.
and the -17 is left
-2x = -17
divide -2 by -17 = 8.5
F(x) = x^2 - 8x + 5
f(-1) = -1^2 - 8(-1) + 5
f(-1) = 1 + 8 + 5
f(-1) = 14 <==
First you need to set up an equation y = mx + b. m would be the monthly charge and b would be the one time fee. x represents the number of months.
To solve for the number of months with a total price of 240 we substitute 240 in for y and solve for x.
240 = 25x + 40
subtract 40 from each side
200= 25x
divide by 25
8 = x
8 months
10 + 7r = 45
7r = 35
r = 5
5 miles
28 gallons of paint to paint the walll
