subsb2 <- function(A){
  n<-ncol(A)-1
  x<-rep(0,n)
  for(i in n:1){
    if(i<n){
      temp <- A[i,1:n]%*%x
      x[i] <- (A[i,n+1]-temp)/A[i,i]
    }
    else{
      x[i] <- A[i,n+1]/A[i,n]
    }
  }
  x
}
subsb2(hasil)