J jwnichols21 Full Member 10+ Year Member Sep 12, 2011 #1 Advertisement - Members don't see this ad I know there's an easy way to do this..it's just been so long since seeing this type of problem. Can anyone help? Thanks. Which is the third term in the expansion of (x+3) ^5 ? a) 10x^3 b) 9x^3 c) 90x^3 d) 90x^4 e) 10x^4 Answer is C.
Advertisement - Members don't see this ad I know there's an easy way to do this..it's just been so long since seeing this type of problem. Can anyone help? Thanks. Which is the third term in the expansion of (x+3) ^5 ? a) 10x^3 b) 9x^3 c) 90x^3 d) 90x^4 e) 10x^4 Answer is C.
N NewBee12 Full Member 10+ Year Member Sep 15, 2011 #2 In general : (a+b)^n = a^n + n(a)^(n-1)b + [n(n-1)/2]a^(n-2)b^2 +........+b^n (x+3)^5 = x^5 +5x^4(3) + [(5)(4)/2]x^3(3)^2 +......+3^5 =x^5 +60x^4 + 90x^3+.......+3^5 Upvote 0 Downvote
In general : (a+b)^n = a^n + n(a)^(n-1)b + [n(n-1)/2]a^(n-2)b^2 +........+b^n (x+3)^5 = x^5 +5x^4(3) + [(5)(4)/2]x^3(3)^2 +......+3^5 =x^5 +60x^4 + 90x^3+.......+3^5
