99×22 88×33
=(100-1)×22 =11×8×11×3
=100×22-1×22 =11×11×8×3
=2200-22 =121×24
=2178 =2904
满意请采纳,不懂的题都可以问我
99×22=(100-1)×22=2200-22=2178
88×33=(90-2)×33=90×33-2×33=2970-66=2904