Let B = number of bagels.
Let M = number of muffins.
10B + 4M = 13.00
5B + 8M = 14.00
To eliminate M, multiply the first equation by -2: -20B - 8M = -26.00
Leave the second equation alone: 5B + 8M = 14.00
Add down the columns: -15B = -12.00
Divide by -15: B = 0.80
Substitute this back into the equation: 5B + 8M = 14.00 ---> 5(0.80 + 8M = 14.00
---> 4.00 + 8M = 14.00
---> 8M = 10.00
M = 1.25