Answer:
Step-by-step explanation:
(1+x)^6 = (1+3)^3 x (1+3)^3
(1+3x+ 3x^2+x^3) x (1+3x+ 3x^2+x^3)
1+ 6x+15x^2+20x^3+15x^4+6x^5+x^6
