what is the sqare root of 81?

Question

details how you got your answer give examples for 2pointget credit....

Answer 1

9, since 9*9=81

Answer 2

Um, 9. I'm not sure what you man "how you got your answer." Unless you are extremely gifted in language, you are obviously out of the second grade, where you should have learned your times tables. 9 x 9 = 81.

Now you could say that x^2 = 81, so x^2 - 81 = 0. You can factor this to (x + 9)(x - 9) = 0. This gives you two roots, x = 9 and x = -9. However, the "square root" is always the positive answer, so that means x = 9.

You could also use the quadratic equation to find the roots of x^2 - 81 = 0. A = 1, B = 0, C = -81

(-1 +/- sqrt(b^2 - 4 * 1 * -81))/(2 * 1)

(0 +/- sqrt(0 + 324))/2

+/- 18/2

+/- 9

Answer 3

That is a mathematical given. Square root of number A is number B multiplied by itself that will give you number A.

1 x 1 = 1
2 x 2 = 4
3 x 3 = 9
4 x 4 = 16
5 x 5 = 25
6 x 6 = 36
7 x 7 = 49
8 x 8 = 64
9 x 9 = 81

Answer 4

The square root of 81 is really +9 or -9 because 9 * 9 = 81 and -9 * -9 = 81

but depending on what math course you are in they may only list positive answers

Answer 5

9

Answer 6

9

Answer 7

9

Answer 8

9

Answer 9

9 times 9 = 81

Answer 10

9

Answer 11

9