1. Find all five-digit numbers $\overline{a b c d e}$ that are divisible by 9 and for which $\overline{a c e}-\overline{b d a}=760$.
II/1. The equation $\overline{a c e}-\overline{b d a}=760$ can be rewritten as $100 a+10 c+e-100 b-10 d-a=760$, from which it follows that $e=a$. Now we can divide the equation by 10 and get $10(a-b)+(c-d)=76$. We consider 2 possibilities, namely $c-d=6$ or $c-d=-4$.

In the first case, $c=d+6$ and $a=b+7$. We take into account the condition that the five-digit number is divisible by 9. This means that $a+b+c+d+e=b+7+b+d+6+d+b+7=3 b+2 d+20=$ $3 b+2(d+1+9)$ is divisible by 9. Therefore, $d+1$ is divisible by 3, and since $c-d=6$, it follows that $d=2$. Then $c=8$ and $9$ divides $3(b+2)$, from which, due to $a=b+7$, it follows that $b=1$. In this case, the five-digit number is 81828.

In the second case, $d=c+4$ and $a=b+8$. Therefore, $a=8$ and $b=0$ or $a=9$ and $b=1$. If $a=8$, from the condition $9 \mid(a+b+c+d+e)=8+2 c+4+8$ it follows that 9 divides $2 c+2$. Thus, $c=8$, but then $d=c+4=12$ is not a digit. If, however, $a=9$, from the condition $9 \mid(a+b+c+d+e)=10+2 c+4+9$ it follows that 9 divides $2 c+5$. Thus, $c=2$ and the five-digit number is 91269.