Answer: We are given a 4-digit number in the form 7ab9, and we know that it is a perfect square. We need to find the value of a + b.
Step-by-step explanation: Any number that can be written as the square of an integer is said to be a perfect square. Since the final digit of a perfect square may only be one of the following: 0, 1, 4, 5, 6, or 9, we can use this information to determine whether or not 7ab9 is a perfect square.
Given that 7ab9's last digit is 9, it is likely that its square root will have a last digit of either 3 or 7.
In light of the knowledge that a + b equals 10, we can attempt other numbers for a and b that meet this requirement:
A + B = 3 + 7 = 10 if a = 3 and b = 7.
As a result, if an is equal to 3, and the value of b is 7, the sum a + b will indeed be 10.