Question

$\frac{a - 2}{a + 3} = \frac{a + 5}{a - 4}$
me ajudem
​

Answer 1

Resposta:

${a-2\over a+3}={a+5\over a-4}\\ \\ multiplica~~cruzado\\ \\ (a-2)(a-4)=(a+3)(a+5)\\ \\ a^2-4a-2a+8=a^2+5a+3a+15\\ \\ a^2-6a+8=a^2+8a+15\\ \\ \not a^2-\not a^2-6a-8a=15-8\\ \\ -14a=7~~~\times(-1)\\ \\ 14a=-7\\ \\ a=-{7\over14}=-{1\over2}$