If a and b are positive integers and (a-1)(b+1)=0 , which of the following must be true?
A)a>b
B)a<b
C)a=b
D)a=1
E)b=1

do you have any tips on how to deal with this type of question?

To get this one, you need to read super carefully. For that equation to be true, either a – 1 = 0, or b + 1 = 0 (or both). However, since the question says a and b are positive integersb + 1 cannot be zero. Therefore, a – 1 must be zero, which means a must equal 1.

Leave a Reply