Question

1пример:
2х+1=2
8,1=1,8
2х+1=9
2х=9-1
2х=8
Х=4

Answer 1

$\dfrac{2x+1}{8,1}=\dfrac2{1,8}\\\dfrac{20x+10}{81}=\dfrac{10}{9}\\20x+10=90\\20x=80\\x=4$

$\dfrac{3x-1}{3,5}=\dfrac{2,8}{0,7}\\\dfrac{30x-10}{35}=\dfrac{28}{7}\\30x-10=140\\30x=150\\x=5$

$\dfrac{1,4}{2x-1}=\dfrac{2,1}{7,5}\\\\\dfrac{7}{10x-5}=\dfrac{7}{25}\\\\\dfrac{10x-5}{7}=\dfrac{25}{7}\\\\10x-5=25\\10x=30\\x=3$