Question

решите уравнение x²+13x /x-4 =x²-15 /4-x .

Answer 1

$\frac{x^2+13x}{x-4} = \frac{x^2-15}{4-x}\\\\ \frac{x^2+13x}{x-4} - \frac{x^2-15}{4-x}=0\\\\ \frac{x^2+13x}{x-4} + \frac{x^2-15}{x-4}=0\; \; |*x-4 \neq 0,\; \; x \neq 4\\\\x^2+13x+x^2-15=0\\\\2x^2+13x-15=0\\\\D=13^2-4*2*(-15)=169+120=289=17^2\\\\x_1= \frac{-13+17}{2*2} = \frac{4}{4}=1;\; \; x_2= \frac{-13-17}{2*2}= \frac{-30}{4}=-7,5$