Question

x2 - 9

Answer 1

a^2-b^2=(a+b)(a-b)

Answer 2

x2-9

Final result :

(x + 3) • (x - 3)
Step by step solution :

Step 1 :

Simplify x2 - 9
Trying to factor as a Difference of Squares :

1.1 Factoring: x2-9

Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)

Proof : (A+B) • (A-B) =
A2 - AB + BA - B2 =
A2 - AB + AB - B2 =
A2 - B2

Note : AB = BA is the commutative property of multiplication.

Note : - AB + AB equals zero and is therefore eliminated from the expression.

Check : 9 is the square of 3
Check : x2 is the square of x1

Factorization is : (x + 3) • (x - 3)

Final result :

(x + 3) • (x - 3)