To find the square root of 81, follow these steps:
1. Understand that finding the square root of a number is determining a value that, when multiplied by itself, gives the original number. In this case, we want a number that, when squared, equals 81.
2. Let’s denote the square root of 81 as [tex]\( \sqrt{81} = x \)[/tex]. This means that [tex]\( x^2 = 81 \)[/tex].
3. Test the possible options given:
- For option a) 7: [tex]\( 7^2 = 49 \)[/tex], which is not equal to 81.
- For option b) 8: [tex]\( 8^2 = 64 \)[/tex], which is not equal to 81.
- For option c) 9: [tex]\( 9^2 = 81 \)[/tex], which is equal to 81.
- For option d) 10: [tex]\( 10^2 = 100 \)[/tex], which is not equal to 81.
4. The correct option is the one where [tex]\( x^2 = 81 \)[/tex]. From the options given, only [tex]\( 9 \times 9 = 81 \)[/tex].
Therefore, the square root of 81 is [tex]\( 9 \)[/tex]. The correct answer is c) 9.
