Thermo chemistry help ASAP?

Question

consider the reaction that occurs when nitroglycerin explodes :

4 C3H5O9N3 ---> 12 Co2 + 6N2 +O2 +10H2O H = -7217 kJ

calculate the amount of heat transferred when 4.5g of nitroglycerin explodes at constant pressure (.answer is 35.75kJ)

I'm not good at thermo chemistry and i don't understand what steps need to be taken

Answer 1

Moles C3H5O9N3 = 4.5 g / 227.0872 g/mol =0.0198

4 moles : 7217 kJ = 0.0198 : x

x =  35.75 kJ