13.) 15
14.) 13
15.) 8
16.) 5
17.) 12
18.)16
3(x-1)=4(1+x)+5
3x-3=4+4x+5
3x-3=4x+9
-3x -3x
-3=x+9
-9 -9
-12=x
Profits = 3.009(number of pizzas) - 77.131
Profits = 3.009(275) - 77.131 = 750.344
Step-by-step explanation:
9) given

10)standard form equation: y=mx+c
where m = slope and c = y-intercept
given m = 8, c = 12,
equation of line :

(4/(x+4-2))/x+1
4/(x+2)=x/4+1/2
(x/4+1/2)/x+1
x=-2/5