Question

РЕШЕНИЕ НА ЛИСТКЕ ПОЖАЛУЙСТА !!! И все подробно 45 баллов!!

Answer 1

Задание 1

$\bf\displaystyle\sqrt{\frac{2x-8}{4}}=3\\\\\sqrt{\frac{2(x-4)}{4}}=3\\\\\sqrt{\frac{x-4}{2}}=3\\\\(\sqrt{\frac{x-4}{4}})^{2}=9\\\\\frac{x-4}{2} = 9\\\\x-4=18\\\\x=18+4=22$

Задание 2

$\bf\displaystyle\sqrt{23-7x}=3\\\\(\sqrt{23-7x})^{2}=9\\\\-7x=9-23=-14\\\\x=2$

Задание 3

$\bf\displaystyle\sqrt{12-x}=x\\\\(\sqrt{12-x})^{2}=x^{2}\\\\12-x=x^{2}\\\\\\\\x^{2}+x-12=0\\\\D=b^{2}-4ac=1-4(1)(-12)=49=7^{2}\\\\x_{1}=\frac{-b+\sqrt{D}}{2a}=\frac{-1+7}{2\cdot1}=3\\\\x_{2}=\frac{-b-\sqrt{D}}{2a}=\frac{-1-7}{2\cdot1}=-4$

Задание 4

$\bf\displaystyle\sqrt{\frac{2}{3x-7}}=1\\\\(\sqrt{\frac{2}{3x-7}})^{2}=1\\\\2=3x-7\\\\\\\\3x-7=2\\\\3x=9\\\\x=3$