[c++] 'was not declared in this scope' error

#include <iostream>
using namespace std;
class matrix
{
    int a[10][10],b[10][10],c[10][10],x,y,i,j;
    public :
        void degerler();
        void ters();
};
void matrix::degerler()
{
    cout << "Satirlari giriniz: "; cin >> x;
    cout << "Sütunlari giriniz: "; cin >> y;
    cout << "Ilk matris elamanlarini giriniz:\n\n";
    for (i=1; i<=x; i++)
    {
        for (j=1; j<=y; j++)
        {
            cin >> a[i][j];
        }
    }
    cout << "Ikinci matris elamanlarini giriniz:\n\n";
    for (i=1; i<=x; i++)
    {
        for (j=1; j<=y; j++)
        {
            cin >> b[i][j];
        }
    }
}

void matrix::ters()
{
    cout << "matrisin tersi\n";
    for (i=1; i<=x; i++)
    {
        for (j=1; j<=y; j++)
        {
    if(i==j)
    {
    b[i][j]=1;
    }
    else
    b[i][j]=0;
    }
}
float d,k;
    for (i=1; i<=x; i++)
    {
    d=a[i][j];
        for (j=1; j<=y; j++)
        {
    a[i][j]=a[i][j]/d;
            b[i][j]=b[i][j]/d;
    }
        for (int h=0; h<x; h++)
        {
            if(h!=i)
    {
       k=a[h][j];
               for (j=1; j<=y; j++)
               {
                    a[h][j]=a[h][j]-(a[i][j]*k);
                    b[h][j]=b[h][j]-(b[i][j]*k);
               }
    }
    count << a[i][j] << "";
    }
    count << endl;
}  
}
int main()
{
    int secim;
    char ch;    
    matrix m;
    m.degerler();
    do
     {
    cout << "seçiminizi giriniz\n";
    cout << " 1. matrisin tersi\n";
    cin >> secim;
    switch (secim)
    {
        case 1:
            m.ters();
            break;
    }
    cout << "\nBaska bir sey yap/n?";
    cin >> ch;
    }
    while (ch!= 'n');
    cout << "\n";
    return 0;
}