Question

Помогите с номером 1249 1),2).3) эти

Answer 1

$1)\; \; \frac{2}{5-x} = \frac{7}{3+x}\; \; ,\; \; \; x\ne 5\; ,\; \; x\ne -3\\\\2(3+x)=7(5-x)\\\\6+2x=35-7x\\\\9x=29\\\\x= \frac{29}{9}=3\frac{2}{9}\\\\2)\; \; \frac{x+4}{6}= \frac{7}{3,36} \\\\x+4= \frac{7\cdot 6}{3,36}\\\\x+4=12,5 \\\\x=8,5\\\\3)\; \; \frac{2,8}{5,2}=\frac{8,4}{-3+x}\; ,\; \; \; x\ne 3\\\\-3+x=\frac{8,4\cdot 5,2}{2,8}\\\\x-3=15,6\\\\x=18,6$