Question

Ребята, добрый всем вечер, вы поможите я надеюсь мне? Если да то задание вот.

Answer 1

1) 2x - 15 = 7 - 2x
2x + 2x = 7 + 15
4x = 22
x = 5,5

$6x + \frac{3}{5} =2 \frac{1}{5} \\\\ 6x + 0,6 =2,2\\\\6x=2,2-0,6\\\\6x=1,6\\\\x= \frac{8}{5} :6\\\\x= \frac{8}{5*6}= \frac{4}{15} \\\\\\ \frac{3}{x-6}= \frac{2}{2x-9}\\\\ \frac{3}{x-6}- \frac{2}{2x-9}=0\\\\ \frac{6x-27-2x+12}{(x-6)(2x-9)}=0\\\\ \frac{4x-15}{(x-6)(2x-9)} =0$

x - 6 ≠ 0        ⇒  x ≠ 6
2x - 9 ≠ 0      ⇒  x ≠ 4,5

4x - 15 = 0
4x = 15
x = 3,75


6x² + x - 1 = 0
D = 1² - 4 * 6 * (- 1) = 1 + 24 = 25 = 5²
$x_{1}= \frac{-1+5}{12} = \frac{4}{12}= \frac{1}{3}\\\\ x_{2}= \frac{-1-5}{12}= \frac{-6}{12}=-0,5\\\\\\6+ \frac{7}{x} =x\\\\6+ \frac{7}{x} -x=0\\\\ \frac{6x+7- x^{2} }{x} =0\\\\ \frac{ x^{2} -6x-7}{x} =0\\\\x \neq 0\\\\ x^{2} -6x-7=0\\\\D=(-6) ^{2} -4*1*(-7)=36+28=64=8 ^{2}\\\\ x_{1} = \frac{6+8}{2}=7\\\\ x_{2}= \frac{6-8}{2}=-1$