0\\\\x_1x_2 = -8 = -8*1\\\\ x_1+x_2 = -7 = -8 + 1\\\\ x_1 = 1, x_2 = -8\\\\ (x-1)(x+8) > 0\\\\ x \in (-\infty,-8) \cup (1,+\infty)" alt="1 \ a) \ x^2+7x-8 > 0\\\\x_1x_2 = -8 = -8*1\\\\ x_1+x_2 = -7 = -8 + 1\\\\ x_1 = 1, x_2 = -8\\\\ (x-1)(x+8) > 0\\\\ x \in (-\infty,-8) \cup (1,+\infty)" align="absmiddle" class="latex-formula">
0\\\\ 3t^2-2t-8 = 0\\\\ t_1t_2 = -\frac{8}{3} = -\frac{4}{3}*2\\\\ t_1+t_2 = \frac{2}{3} = \frac{6}{3} - \frac{4}{3} = 2 - \frac{4}{3}\\\\ t_1 = -\frac{4}{3}\\\\ t_2 = 2\\\\ \sqrt{x} = 2\\\\ \fbox{x = 4} " alt="2 \ a) \ 3x - 2\sqrt{x}-8 = 0\\\\ \sqrt{x} = t\\\\ t > 0\\\\ 3t^2-2t-8 = 0\\\\ t_1t_2 = -\frac{8}{3} = -\frac{4}{3}*2\\\\ t_1+t_2 = \frac{2}{3} = \frac{6}{3} - \frac{4}{3} = 2 - \frac{4}{3}\\\\ t_1 = -\frac{4}{3}\\\\ t_2 = 2\\\\ \sqrt{x} = 2\\\\ \fbox{x = 4} " align="absmiddle" class="latex-formula">
0\\\\ 2x+15 = x^2\\\\ x^2-2x-15 = 0\\\\ x_1x_2 = -15 = 5*(-3)\\\\ x_1+x_2 = 2 = 5 - 3\\\\ x_1 = 5, \ x_2 = -3\\\\ \fbox{x = 5} " alt="b) \sqrt{2x+15} = x\\\\ x > 0\\\\ 2x+15 = x^2\\\\ x^2-2x-15 = 0\\\\ x_1x_2 = -15 = 5*(-3)\\\\ x_1+x_2 = 2 = 5 - 3\\\\ x_1 = 5, \ x_2 = -3\\\\ \fbox{x = 5} " align="absmiddle" class="latex-formula">