Question

teorema de tales !!!!
3x x+3
x+6 x
multiplica cruzado:
3x*x = (x+6)*(x+3)

até essa parte eu entendi, só não sei oq eu faço agora

Answer 1

$> resolucao \\ \\ \geqslant teorema \: de \: tales \\ \\ \frac{3x}{x + 6} = \frac{x + 3}{x} \\ \\ 3x(x) = (x + 6)(x + 3) \\ \\ 3x {}^{2} = x {}^{2} + 3x + 6x + 18 \\ \\ 3 {x}^{2} - {x}^{2} - 9x = 18 \\ \\ 2 {x}^{2} - 9x - 18 = 0 \\ \\ > \: resolvendo \: a \: equacao \: do \: 2 \: grau \\ \\ delta = ( - 9) {}^{2} - 4.2.( - 18) \\ delta = 81 + 144 \\ delta = 225 \\ delta = \sqrt{225} \\ delta = + - 15 \\ \\ \\ x1 = \frac{9 + 15}{4} \\ \\ x1 = \frac{24}{4} \\ \\ x1 = 6 \\ \\ \\ x2 = \frac{9 - 15}{4} \\ \\ x2 = \frac{ - 6}{4} \\ \\ x2 = - \frac{3}{2} \\ \\ \\ \\ s \: \: > \: \: ( \: \: 6 \: \: \: \: . \: \: \: \: - \frac{3}{2} \: \: \: \: ) \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant$