Question

4-7х^      6х^2

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2-х        2-х

            3

при х= - --

            4

Answer 1

$frac{4-7x^2}{2-x}-frac{6x^2}{2-x}=frac{4-7x^2-6x^2}{2-x}=frac{4-13x^2}{2-x}$

 

$frac{4-13x^2}{2-x}=frac{4-13cdot(frac{3}{4})^2}{2-frac{3}{4}}=frac{4-13cdotfrac{9}{16}}{frac{5}{4}}=frac{4(4-frac{117}{16})}{5}=frac{16-frac{117}{4}}{5}=frac{-frac{53}{4}}{5}==-frac{53}{5cdot4}=-frac{53}{20}=-2,65$