不懂算式错在哪里了，求指导

Question

#include <stdio.h>
#include <math.h>
int main()
{
int d;
double c;
scanf("%d",&d);
5000=d*(0.004*(pow(1+0.004,c))/(5000*(pow(1+0.004,c))-1);
printf("%.2f",c);
}

Answer 1

5000=？常量不能放左边