Jan bought 6 cookies and 4 doughnuts for 3.50. Tom bought 12 cookies and 5 doughnuts got 5.23. Write and solve a system of equations to find the cost of one cookie

0.19 for one cookie and 0.59 for one doughnut

x for how much one cookie costs and y for how much one doughnut costs

6x+4y=3.5

12x+5y=5.23

solve by substitution: (elimination would work too)

4y=3.5-6x

y=0.875-1.5x

12x+5 (0.875-1.5x) = 5.23

12x+4.375x-7.5x=5.23

4.5x=0.855

x=0.19

now use x to solve for y:

6 (0.19) + 4y=3.5

1.14+4y=3.5

2.36=4y

y=0.59

Check the work: 6 (0.19) + 4 (0.59) = 3.5