99²+99÷
=99×99+99×1
=99×(99+1)
=99×100
=9900
4.9-(5分之3+2.4÷2又3分之2)
=4.9-(3/5+2.4÷2又2/3)
=4.9-[3/5+2.4×(3/8)]
=4.9-(3/5+0.9)
=4.9-(0.6+0.9)
=4.9-0.9-0.6
=4-0.6
=3.4
99²+99÷
=99×99+99×1
=99×(99+1)
=99×100
=9900
4.9-(5分之3+2.4÷2又3分之2)
=4.9-(3/5+2.4÷2又2/3)
=4.9-[3/5+2.4×(3/8)]
=4.9-(3/5+0.9)
=4.9-(0.6+0.9)
=4.9-0.9-0.6
=4-0.6
=3.4