Question

Aflati multimea solutiilor inecuatiei:

$2C_{10} ^{x} \ \textless \ C_{10} ^{x-1}$

Answer 1

Răspuns:

2C₁₀ˣ<C₁₀ˣ⁻¹

2*10!/x!*(10-x)!<10!/(x-1)!*(10-(x-1))l:10!

2/x!*(10-x)!<1/(x-1)!(10-x+1)!

2/(x-1)!*x*(10-x)!<1/(x-1)!*(11-x)!

2/x*(10-x)!<1/(10-x)!*(11-x)

2/x<1/(11-x)=>

x/2>11-x

x>22-2x

x+2x.>22

x>22/3≈7,3=>

x∈{8,9,10....}

Explicație pas cu pas:

Answer 2

Raspuns: x={8,9,10}

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