Answer:
78
Explanation:
The square of 9 is 9^2 which implies 9 × 9 = 81
Let the unknown number be represented by X. Thus,
9^2 - x = 3
81 - x = 3
Add x to both sides
81 - x + x = 3 + x
81 = 3 + x
Subtract 3 from both sides
81 - 3 = 3 - 3 + x
78 = x
x = 78
Check
81 - x = 3
Since x = 78
81 - 78 = 3