Given the standard heats of reaction

Question

Reaction ∆H0
M(s) + 2 X2(g) → MX4(g) −123.7 kJ/mol
X2(g) → 2 X(g) +297.3 kJ/mol
M(g) → M(s) −25.1 kJ/mol
calculate the average bond energy for a single
M X bond.
Answer in units of kJ/mol