Question

factorixe x^4-81 using algebraic identity ​

Answer 1

Step-by-step explanation:

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 : 81 is the square of 9

Check : x4 is the square of x2

Factorization is : (x2 + 9) • (x2 - 9)