B3
1)3^4.38-3^4.37
=3^4(38-37)
=3^4.1
=3^4=81
2)608÷2^4-592÷2^4
=(608-592)÷2^4
=16÷2^4
=16÷16=1
3)5³×678910-5³×678909
=5³×(678910-678909)
=5³×1
=125
4)(5^3015 - 5^3013)÷ 5^3013
=(5^3015÷ 5^3013) - (5^3013÷ 5^3013)
=5²- 1
=25-1=24
5)(3^13×99 - 15×3^14)÷(3^17÷3²)
=(3^14×33-15×3^14)÷(3^15)
=3^14(33-15)÷3^15
=3^14 × 18 ÷ 3^15
=3^15 × 6 ÷ 3^15
=6
6)3²×9876543-3² ×9876541
=3²×(9876543-9876541)
=9×2=18
7)4²×444446 - 4³×111111
=16×444446 - 64×111111
=2^4×444446 - 2^5×111111
=2^4×444446 - 2^4×2×111111
=2^4×(444446-222222)
=2^4×222224
=3555584
