Question

Solve a^2 - 81 = 0 by factoring. Select all possible answers.


-9


No solution


9


Infinite solutions


0

Answer 1

It's 9 and -9.
(a+9)(a-9)=0.

Answer 2

so, the answer is -9 and 9?

Answer 3

You need to factor the difference of two squares.
That factors like this:
\(a^2 - b^2 = (a + b)(a - b) \)

In your case, you have
\(a^2 - 81 = 0\)

\(a^2 - 9^2 = 0\)

\((a + 9 )(a - 9) = 0\)

\(a + 9 = 0\) or \(a - 9 = 0\)

\(a = -9\) or \(a = 9\)

Answer 4

Yes.

Answer 5

What about
Solve n^2 - 3n = 0 by factoring. Select all possible answers.


Infinite solutions


No solution


Others that aren't listed here.


3


0

Answer 6

Factor out a common term out of the left side.
Both terms have n in them.