Question

81 y ² - 36=0





ТЕРМІНОВО дам 100 балів​

Answer 1

$\displaystyle\bf\\81y^{2} -36=0 \ |:9\\\\9y^{2} -4=0\\\\(3y)^{2} -2^{2} =0\\\\(3y-2)\cdot(3y+2)=0\\\\\\\left[\begin{array}{ccc}3y-2=0\\3y+2=0\end{array}\right\\\\\\\left[\begin{array}{ccc}3y=2\\3y=-2\end{array}\right\\\\\\\left[\begin{array}{ccc}y_{1} =\dfrac{2}{3} \\y_{2} =-\dfrac{2}{3} \end{array}\right\\\\\\Otvet \ : \ -\frac{2}{3} \ ; \ \frac{2}{3}$

Answer 2

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