Question

factorisation
${x }^{2} + 42 - 64$
factorise it​

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 : 22 is not a square !!

Ruling : Binomial can not be factored as the difference of two perfect squares.

Final result :

x2 - 22