第1个回答 2021-04-24
99x78+33x66
=99x78+33x3X22
=99x(78+22)
=99x100
=9900
第2个回答 2021-04-24
99×78+33×66
=99×78+33×3×22
=99×78+99×22
=99×(78+22)
= 99×100
=9900
第3个回答 2021-04-24
解:99x78+33x66
=9x11x2x39+3x6x11x11
=18x11x39+18x11x11
=198x39+198x11
=198x(39+1)
=198x40
=7920