Prove the following statement about divisibility of integers: If d|(a+b) and d|a, then d|b. Solution we can write d =(a+b) where is an integer; also d= \'a where \' is an integer \'a = (a+b) => (\'-)a = b => {(\'-)/}a = b.........(1) If d is divisible by b then d=\"b => d=\" {(\'-)/}a [\" is an integer] [Putting value of b from (1)] \" {(\'-)/} is also an integer and thus d is divisible by a as given in the ques....... Thus our assumption is correct Thus d is divisible by b........ Hope you understand the explanation.