Recent content by ukee1593

Problem solved ... First of all, note my error in the last line (12C7) * (a)^5 * (-b)^7 + (12C7) * (a)^4 * (-b)^8 = 0 Should be: (12C7) * (a)^5 * (-b)^7 + (12C8) * (a)^4 * (-b)^8 = 0 The negative b on the (-b)^7 comes out the front as it is an odd power ... The other negative...

Homework Statement I'm asked to find (a/b) in the simplest form if the co-efficient of x^8 is zero in the expansion of: (1 + x)(a - bx)^12 Homework Equations Binomial expansion formula ... (a + b)^n = Sum of r --> n (r = 0) (nCr)(a^(n-r) * b^r The Attempt at a Solution...