Bentley went into a bakery and bought 4 donuts and 10 cookies, costing a total of $23. skylar went into the same bakery and bought 8 donuts and 6 cookies, costing a total of $25. determine the price of each donut and the price of each cookie.

Donuts cost $2.00 and Cookies cost $1.50

Step-by-step explanation:

D = cost of a donut

C = cost of a cookie

4D + 10C = $23.00

8D + 6C = $25.00

Eliminate a variable when subtracting the two equations.  Change both values with C to 60 in order to eliminate the C variable and solve for D.

80D + 60C = $250.00 subtracted from 24D + 60C = $138

56D = $112.00  (Divide by 56 to single out the variable)

56D/56 = $112.00/56

D = $2.00

Use the D value to solve for C.

4(2) + 10C = $23.00

8 + 10C = $23.00

8 - 8 + 10C = $23.00 - 8

10C = $15.00

10C/10 = $15/10

C = $1.50

Check:

Bentley:  

4D + 10C = $23

4(2) + 10(1.50) = $23

8 + 15 = $23

23 = 23

Skylar:

8D + 6C = $25

8(2) + 6(1.50) = $25

16 + 9 = $25

25 = 25

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)