解:58×199等于( 11542 ) ∵已知需求出58×199等于多少 X × (Y - 1)= X × Y - X ∴58 × 199 = 58 × (200 - 1) = 58 × 200 - 58 × 1 = 11600 - 58 = 11542 答:58×199等于11542
58x199=58x(200-1)=58x200-58=11600-58=11542