Question

Помогите срочно!!!
$\frac{21y^{2} + 11y - 2 \: }{15y ^{2} + 16y + 4 }$
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Answer 1

$\frac{21y^2+11y-2}{15y^2+16y+4}=\frac{21(y+\frac{2}{3})(y-\frac{1}{7})}{15(y+\frac{2}{3})(y+\frac{2}{5})}=\frac{(3y+2)(7y-1)}{(3y+2)(5y+2)}=\frac{7y-1}{5y+2}\\\\\\21y^2+11y-2=0\; ,\; \; D=289=17^2\; ,\; \; y_1=\frac{-11-17}{42}=-\frac{28}{42}=-\frac{2}{3}\; ,\\\\y_2=\frac{-11+17}{42}=\frac{6}{42}=\frac{1}{7}\\\\\\15y^2+16y+4=0\; ,\; \; D=16\; ,\; y_1=\frac{-16-4}{30}=-\frac{2}{3}\; ,\; y_2=\frac{-16+4}{30}=-\frac{2}{5}$