#include <stdio.h>

void main(void)
{
static float x[5][5] = {{2, 4, 3, 7, 9},
{4, 3, 7, 9, 6},
{6, 5, 9, 4, 1},
{8, 2, 6, 3, 7},
{7, 1, 3, 5, 9}};

static float w[5][5] = {{0.2, 0.5, 0.8, 0.1, 0.6},
{0.3, 0.7, 0.8, 0.1, 0.2},
{0.9, 0.3, 0.5, 0.7, 0.4},
{0.7, 0.1, 0.3, 0.5, 0.9},
{0.4, 0.2, 0.5, 0.1, 0.7}};

int i,j;
float sum,sumsum;
for(i=0; i<5; i++){
sum = 0;
sumsum = 0;
for(j=0; j<5; j++){
sum = sum + x[i][j] * w[i][j];
sumsum += sum;
}
printf("合計=%f\n",sum);
}
printf("合計=%f\n",sumsum);
}

すいません、こういうことでしょうか？まだ不具合が…。