Please solve it for me I didn't under stsnd it .

Dear Student,
a) False. An algebraic can have one term also.
b) True. a+b+c has three terms so it is trinomial,while abc is one term.
c) LHS: 200-(50)=150
RHS:(200-100)-50=100-50=50
False.
d) LHS: 83+(40+35)=83+75=158
RHS: (83+40)+35=123+35=158
True. 
Regards!