6² + √81 - 5² = ?
6² = 36
√81 = 9
5² = 25
So, 6² + √81 - 5² = 36 + 9 - 25 = 20
To calculate the given expression step-by-step, let's start by evaluating each part:
1) 6² = 6 * 6 = 36 (since squaring a number means multiplying it by itself)
2) √81 = square root of 81 = 9 (since the square root of 81 is a number that, when multiplied by itself, equals 81)
3) 5² = 5 * 5 = 25
Now, substitute the values we calculated back into the original expression:
36 + 9 - 25 = 45 - 25 = 20
Therefore, 6² + √81 - 5² equals 20.