Question

Simplify (a + b + 6) – (2b – a +3) + (a + b - 3) and write the answer.​

Answer 1

Answer:

8a  3

.

Step-by-step explanation:

The given expression (a+b)  

3

+(a−b)  

3

+6a(a  

2

−b  

2

) can be solved as follows:

(a+b)  

3

+(a−b)  

3

+6a(a  

2

−b  

2

)

=a  

3

+b  

3

+3a  

2

b+3ab  

2

+a  

3

−b  

3

−3a  

2

b+3ab  

2

+6a  

3

−6ab  

2

 

(∵(x+y)  

3

=x  

3

+y  

3

+3x  

2

y+3xy  

2

,(x−y)  

3

=x  

3

−y  

3

−3x  

2

y+3xy  

2

)

=(a  

3

+a  

3

+6a  

3

)+(b  

3

−b  

3

)+(3a  

2

b−3a  

2

b)+(3ab  

2

+3ab  

2

−6ab  

2

)

=8a  

3

 

Hence, (a+b)  

3

+(a−b)  

3

+6a(a  

2

−b  

2

)=8a  

3

.