binomial theorm (1 Viewer)

nrumble42 · May 30, 2017

1. in the expansion of (2 +3x)^n, the coefficients of x^3 and x^4 are in the ratio 8:15. Find n

2. in the expansion of (x+a)^3(x+b)^5, the coefficients of x^7 and x^6 are 9 and 12 respectively. Find the values of a and b.

integral95 · May 30, 2017

$1. \ \ \frac{\binom{n}{3}(3)^3(2)^{n-3}}{\binom{n}{4}(3)^4(2)^{n-4}} = \frac{8}{15}$

From there you expand and simplify the algebra then solve for n.

integral95 · May 30, 2017

binomial theorm (1 Viewer)

nrumble42

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integral95

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integral95

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