a, \(4^{100}-4^{99}=4^{99}\left(4-1\right)=4^{99}\cdot3⋮3\)
vậy......
b, \(10^{15}+10^{16}+10^{17}=10^{15}\left(1+10+10^2\right)=10^5\cdot111⋮111\)
vậy.......
a, \(4^{100}-4^{99}=4^{99}\left(4-1\right)=4^{99}\cdot3⋮3\)
vậy......
b, \(10^{15}+10^{16}+10^{17}=10^{15}\left(1+10+10^2\right)=10^5\cdot111⋮111\)
vậy.......
Tính nhanh các tổng sau
a)11+12+13+14+15+16+17+18+19 b)1+2+3+4+5+................+99+100
c)2+4+6+8+10+.........100 d)5+10+15+20+25+......+95+100
GIÚP MÌNH VỚI !
Tính hợp lí
1) -145.(13 - 57) + 57.(10 -145)
2) 17.(15 - 16) + 16.( 17- 20)
3) -38.(25 - 4) + 25.(-4 + 38 )
4) 23.(145 - 17) - 145.(23 - 6)
5) 24.(15 - 4) + 4.(24 - 15)
6) 199.(15 - 17) - 199.(-17 + 5)
7) -39.(5 - 99) + 99.(10 - 39)
1,Chứng minh rằng: 1<1/5+1/6+1/7+....+1/17<2
2,Cho A=1/2× 3/4×5/6×....×99/100
Chứng minh rằng 1/15<A<1/10
1) -145.(13 - 57) + 57.(10 -145)
2) 17.(15 - 16) + 16.( 17- 20)
3) -38.(25 - 4) + 25.(-4 + 38 )
4) 23.(145 - 17) - 145.(23 - 6)
5) 24.(15 - 4) + 4.(24 - 15)
6) 199.(15 - 17) - 199.(-17 + 5)
7) -39.(5 - 99) + 99.(10 - 39)
Số sánh
a, (-1)×2×(-3)×4×(-5)×6×........×(-99)×100
b,(-10)×(-11)×12×13×(-14)×(-15)×16×17×.......×100×101
cho A = 1/2 . 3/4 . 5/6 . .... . 99/100
Chứng minh rằng 1/15 <A<1/10
Cho A = 1/2 . 3/4 . 5/6.............. . 99/100. Chứng minh rằng 1/15 < A < 1/10.
helpppppppppppppppppppppppppppppp !!!!!!!!!!!
cho a=1/2.3/4.5/6. ... .99/100;b=2/3.4/5. ... .100/101;c=1/2.2/3.3/4. ... 98/99 a, so sánh a, b,c b,chứng minh a.c<a^2<1/100 c,chứng minh 1/15<a<1/10
so sánh
a, A=\(\frac{10^{17}-1}{10^{16}-1}vaB=\frac{10^{16}+2}{10^{15}+2}\)
b,\(C=\frac{2017^{15}+1}{2017^{16}+1}vaO=\frac{2017^{16}-1}{2017^{17}-1}\)
c,\(E=\frac{99^{15}-1}{99^{16}-1}vaF=\frac{99^{16}+2}{99^{17}+2}\)