H = ( m : 1 - m *1 ) : ( m *1991 + m + 1 )
H=(m-m):(m*1991+m+1)
H=0:(m*1991+m+1)
H=0
H= (m:1-m X 1) : (m X 1991 + m + 1)
= ( m - m ) : (m X1991 + m +1 )
= 0 : ( m X 1991 + m + 1 )
= 0
H = ( m : 1 - m x 1 ) : ( m x 1991 + m + 1 )
H = ( m - m ) : ( m x 1991 + m + 1 )
H = 0 : ( m x 1991 + m + 1 )
H = 0 ( vì 0 chia cho số nào cũng bằng 0 )
H = ( m : 1 - m $\times$x 1 ) : ( m $\times$x 1991 + m + 1 )
H = ( m - m X 1 ) : ( m X 1991 + m + 1 )
H = 0 : ( m x 1991 + m + 1 )
H = 0
H = ( m : 1 - m *1 ) : ( m *1991 + m + 1 )
H=(m-m):(m*1991+m+1)
H=0:(m*1991+m+1)
H=0
H = ( m : 1 - m *1 ) : ( m *1991 + m + 1 )
H=(m-m):(m*1991+m+1)
H=0:(m*1991+m+1)
H=0