Lllllllllllllllllllllllllllllllllllllllllllllllllllll

Question

Use complete sentences to explain how to easily find the expansion of (x + 2)39.

Answer 1

(x+2)^39

= x^39 + 39x^38(2) +;;;+ nCr(x)^(n-r)(2)^r + ... 39x(2)^38 + (2)^39

each of the 40 terms in the expansion is a product of x and 2, each raised to a power that decreases for x and increases for 2, and with a coefficient which can be found on the 39th row of Pascal's Triangle or calculated as a combination, nCr where n starts at 39 and r starts at 0, n decreases by 1 each term and r increases by 1 each term.