Question

question no 21. (a+b)³-a-b?factories ​

Answer 1

Step-by-step explanation:

(a+b)*3-(a+b)

(a+b)[ ( a+b)*2-1]

(a+b) [(a+b)*2-(1)*2]

using formula

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

a+b[ (a+b+1) ( a+b-1) ]

Answer 2

$\sf \: {(a + b)}^{3} - a - b \\ \sf \implies \: {(a + b)}^{3} -( a + b) \\ \sf \implies \: (a + b) \: ( {(a + b})^{2} - {1}^{2} ) \\ \red{ \sf \implies \: (a + b)(a + b + 1)(a + b - 1) }$