Question

Решите три уравнения (80 ): со всеми условиями .

Answer 1

$\frac{4}{ x^{2} -9} -1=\frac{X+1}{3-x} \\\frac{4}{(x-3)(x+3)} -1=\frac{x+1}{3-x} \\4-1*(x-3)(x+3)=(x+1)[-(x+3)]\\4- x^{2} +9=- x^{2} -4x-3\\4- x^{2} +9+ x^{2} +4x+3=0\\4x+16=0\\4x=-16\\x=-16/4=-4$

$x^{2} -1\frac{11}{25} = (\frac{6}{5} )^{2} \\x^{2}=\frac{36}{25} +\frac{36}{25} \\x^{2}=\frac{72}{25} \\x= \sqrt{\frac{72}{25} }=\frac{ \sqrt{72} }{ \sqrt{25} } =\frac{ \sqrt{36*2} }{5} =\frac{6 \sqrt{2} }{5}$

$\frac{3}{4}:|x|+2.4=4.5\\ \frac{3}{4} :|x|=4.5-2.4\\\frac{3}{4} :|x|=2.1\\|x|= \frac{3}{4} :2.1= \frac{3}{4} * \frac{10}{21} = \frac{5}{14} \\x= \frac{5}{14}; x=- \frac{5}{14}$