Question

Решите уравнения |4х+8|=11; | |х|+7|=8; |х+5|=|х-4|. решите вот эти 3 уравнения, !

Answer 1

|4х+8|=11
4х+8=11
4x=11-8
4x=3
x=3/4

Answer 2

$\displaystyle\mathtt{|4x+8|=11;~|x+2|=2,75~\to\left[\begin{array}{ccc}\mathtt{x+2=2,75}\\\mathtt{x+2=-2,75}\end{array}\right\to\left[\begin{array}{ccc}\mathtt{x=0,75}\\\mathtt{x=-4,75}\end{array}\right}$

$\displaystyle\mathtt{||x|+7|=8~\to\left[\begin{array}{ccc}\mathtt{|x|+7=8}\\\mathtt{|x|+7=-8}\end{array}\right\to\left[\begin{array}{ccc}\mathtt{|x|=1}\\\mathtt{|x|=-15}\end{array}\right\to~x=б1}$

$\displaystyle\mathtt{|x+5|-|x-4|=0~\to\left\{{{|x+5|=0}\atop{|x-4|=0}}\right\to\left\{{{x+5=0}\atop{x-4=0}}\right\to\left\{{{x_1=-5}\atop{x_2=4}}\right}$