.
The system of equations is
M + 2T = 737, (1)
2M + T = 778. (2)
Now you can solve it using the Substitution method, or the Elimination method, or the Cramer' rule (determinants).
In nova days, you can even use your pocket calculator with its matrix functions or numerous Internet sites to solve the system.
In particular, such (free of charge) solver is at THIS website
https://www.algebra.com/algebra/homework/Matrices-and-determiminant/cramers-rule-2x2.solver
https://www.algebra.com/algebra/homework/Matrices-and-determiminant/cramers-rule-2x2.solver
I used it, and the solver gave me answer 273 and 232 calories for one Milky-Way and one Twix bar, respectively.