Answer:
(a) 
(c) 
Step-by-step explanation:
(a) To find verify the answer we need to multiplying the equation

Thus, this statement is true.
(b) To find verify the answer we need to multiplying the equation 

Hence, the given statement is false.
(c) To find verify the answer we need to multiplying the equation 

Hence, the given statement is true.
(d) To find verify the answer we need to multiplying the equation

Hence, the given statement is false.