Tính nhanh: a) 11,2 - 7,63 + 8,8 -2,37 ; b) 3,45 * 123 + 4 * 3,45 - 3,45 * 27
Giải thích
a)
11,2−7,63+8,8−2,37=11,2+8,8⏟−7,63+2,37⏟ =20−10 =10
b)
3,45×123+4×3,45−3,45×27=3,45×123+4−3,45×27=3,45×127−3,45×27=3,45×127−27=3,45×100=345
a)
11,2−7,63+8,8−2,37=11,2+8,8⏟−7,63+2,37⏟ =20−10 =10
b)
3,45×123+4×3,45−3,45×27=3,45×123+4−3,45×27=3,45×127−3,45×27=3,45×127−27=3,45×100=345