Answer:
5
Explanation:
(I'm assuming that by m2 and n2 you mean m to the power of 2 and n to the power of 2)
Whenever you have a number to a power, it is the same as that number times itself that power number of times. For example, 3 to the power of 4 is equal to 3 times itself 4 times, which is 3 * 3 * 3 * 3. If we use this and substitute the values in for m and n, we get that 3^2 - 2^2, and since 3^2 is 3 * 3 and 2^2 is 2 * 2 and 3 times 3 is 9 and 2 times 2 is 4, we get that 9 - 4 is 5.
Note: This symbol means to the power of ----> ^