Ответ:

1)5(2х+1)=12

10х+5=12

10х=7

х=0,7

2)

[tex] \frac{1}{2}x \times \frac{3}{23} = \frac{23}{7} \times 4 \\ \frac{3}{46}x = \frac{92}{7} \\ x = 201 \frac{11}{21} [/tex]