HOW DO WE CALCULATE (X+Y)^3

Question

WHAT ARE THE STEPS TO FALLOW WHEN  SIMPLIFYING (X+Y)^3

Answer 1

  Remember that:

(x+y)^3 = (x+y)(x+y)(x+y)

Start with the first two (x+y) and expand:

(x+y)(x+y)

= x(x+y)+y(x+y)

= x^2+xy+yx+y^2

= x^2+2xy+y^2

 

Now you have to multiply this last expression by (x+y) again.  Try setting it up the same way I did here, that is:

(x+y) (x^2+2xy+y^2)

= x(x^2+2xy+y^2) + y(x^2+2xy+y^2)

this way you are just multiplying by x first and then only by y and at the end just group terms as appropriate.  

 

If you need more advice, let me know.