a) (1+2+3+4)^2 và 1^3+2^3+3^3+4^3
(1+2+3+4)^2=1^2+2^2+3^2+4^2
ta có 1^2+2^2+3^2+4^2 < 1^3+2^3+3^3+4^3
vậy (1+2+3+4)^2 < 1^3+2^3+3^3+4^3
b) 19^4 và 16.18.20.22
16.18.20.22=126 720
19^4=19.19.19.19=130 321
vì 130 321 > 126 720
=> 19^4 > 16.18.20.22
phần b chỉ biết cách đấy thôi ,thông cảm
Chung to A = 1 x 2 + 2 x 3 + 3 x 4 + ..... + n x [ n + 1 ] = {[n x [ n + 1 ] x [ n + 2 ] }/3 , n > 0
Cac ban nhanh len nhe ngay mai minh phai nop roi . Ai lam nhanh , dung dau tien minh cho 1 tich
a,\(\left(\frac{-1}{2}\right)^3-\left(\frac{2}{5}x+\frac{1}{3}\right)=3\)
b,\(-2\frac{1}{3}-\left(4\frac{1}{6}-\frac{4}{3}+1\frac{1}{2}\right)\)
AI GIAI DUOC MINH CHO 10 TICK.NHANH NHA MINH DANG CAN GAP
tinh tong hop li:
F=1+2-3-4+5+6-7-8+....(F co 2015 so hang)
ai lam nhanh dung,day du minh tich !!!!!!!!!!!!!!!!!!
bai 1 :thuc hien phep tinh
a)\(\frac{-5}{2}:\left(\frac{3}{4}-\frac{1}{2}\right)\) b) \(11\frac{3}{13}-\left(2\frac{4}{7}+5\frac{3}{13}\right)\) c)\(\left(\frac{-5}{24}+0,75+\frac{7}{12}\right):\left(-2\frac{1}{4}\right)^2\)
AI LAM NHANH VA DUNG THI MK SE TICK CHO NHA
MK DAG CAN GAP !!!!!!! CAC BAN LAM NHANH LEN NHA
cho A =1/2*3/4*5/6*...*99/100
B=2/3*4/5*6/7*...*100/101
C=1/2*2/3*4/5*...*98/99
a) so sanh A, B, C
b) Chung minh: A*C< A^2< 1/10
c) Chung minh: 1/15< A< 1/10
Lam giup minh di ai lam duoc minh tich dung cho
2va1/7:( -1/4-3/28) - 3 và 1/19
1 . Tinh : a , \(\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)\left(1-\frac{1}{14}\right).....\left(1-\frac{1}{5050}\right)\)b,\(\frac{^{2^{19}}.\left(3^3\right)^3+3.5.\left(2^2\right)^9.\left(3^2\right)^4}{\left(2.3\right)^9.2^{10}+\left(3.2^2\right)^{10}}\)c,\(\frac{18.\frac{19}{2}.\frac{20}{3}.\frac{21}{4}.....\frac{36}{19}}{20.\frac{21}{2}.\frac{22}{3}.....\frac{36}{17}}\)giup mjk nha mjk tjk cho
a,\(x^3-\frac{4}{25}x=0\)
b,\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
c\(4.\left(\frac{-1}{2}\right)^3-2.\left(\frac{-1}{2}\right)^2+3.\left(\frac{-1}{2}\right)-1.\left(\frac{-1}{2}\right)^0\)
AI GIAI DUOC MINH CHO 10 TICK
trình bày cách tính nhanh các phép tính sau đây
a)\(\frac{2^8\cdot6}{3^3\cdot5^4}:\frac{8^3\cdot9}{5^3\cdot3^3}-\left(2^{14}+3^{19}\right)\cdot\left(3^{81}+5^{64}\right)\left(2^4-4^2\right)\)
