<span>9x^2-4=0</span>
<span>9x^2 = 4</span>
<span>x^2 = 4/9</span>
<span>x= плюс минус 2\3</span>
<span>
</span>
<span>5х(в квадрате)-20=0</span>
<span>5x^2 = 20</span>
<span>x^2 = 20\5</span>
<span>x^2 = 4</span>
<span>x = плюс минус 2</span>
<span>
</span>
<span><span>0,64-у(в квадрате)=0</span></span>
<span><span>y^2 = 0,64</span></span>
<span><span>y = плюс минус 0.8</span></span>
<span><span>
</span></span>
<span><span><span>z(в квадрате)-7=0</span></span></span>
<span><span><span>z^2 = 7</span></span></span>
<span><span><span>z = плюс минус корень из 7</span></span></span>
<span><span><span>
</span></span></span>
<span>11-z(в квадрате)=0</span>
<span>z^2 = 11</span>
<span>z = плюс минус корень из 11</span>