Use the rows of Pascal's Triangle:
4: 1 4 6 4 1
5: 1 5 10 10 5 1
11: 1 11 55 ...
use those as coefficients of your powers.
For example using row 6,
1 6 15 20 15 6 1
(2x - 3)^6 =
1*(2x^6) + 6*(2x)^5(-3^1) + + 15*(2x^4)*(-3)^2 + ...
= 64x^6 - 576x^5 + 2160x^4 - ...
1) expand (1+3x)^4 using the Binomial Theorem.
2) Use Pascal's Triangle to expand(x+2)^5
3)What is the third term of (a+b)^11?
1 answer
1 answer