Question

x+21=35,3;3x+1 <32,02in N

Answer 1

x+21=35.3
x=35.3-21
x=14.3

3x+1<32.02
3x<32.02-1
3x<31.02
x<31.02:3
x<10.34

Answer 2

$x+21=35,3$
$x=35,3-21$
$\boxed{x=14,3}$

$3x+1\ \textless \ 32,02$
$3x\ \textless \ 32,02-1$
$3x\ \textless \ 31,02$
$x\ \textless \ 31,02:3$
$x\ \textless \ 10,34$
$x=[10,33; 10,32; 10,31.....n...]$