23(x) = 19(10)
2*x+3 = 19
2*x = 16
x = 8
Ответ: 8
2)program 2;
var
k:integer;
<span>
tmp:real;</span><span>
b:string;</span><span>
c:string;</span><span>
i:integer;
</span>
begin
<span>
k:=0; i:=0; tmp:=0;</span><span><span>
write('</span>Введите k:');</span><span>
read(k);</span><span>
repeat</span><span>
tmp:=exp(i*ln(10));</span><span>
str(tmp:0:0, c);</span><span>
b:=b+c;</span><span>
i:=i+1;</span><span>
until length(b) >= k;</span><span>
c:=copy(b, k, 1);</span><span>
writeln(b);</span><span>
writeln('k-я цифра:', c);</span><span>
readln(k);</span>
<span>end.</span>
В нэте есть я это тоже позавчера делал)