if a is a positive integer , and if the units digit of a ^ 2 is 9 and the units digit of ( a + 1 ) ^ 2 is 4 , what is the units digit of ( a + 2 ) ^ 2 ?
"for unit digit of a ^ 2 to be 9 . . . unit digit of a has to be 3 or 7 . . . now for unit digit of ( a + 1 ) ^ 2 to be 4 . . unit digit of a has to be 1 or 7 . . . . from the above two conditions , unit value of a has to be 7 , which will satisfy both the conditions . . . now id unit digit of a is 7 , unit digit of ( a + 2 ) ^ 2 hast to be 1 . answer : a"
power(add(multiply(9, 2), 2), 2)