cho A = 2/1 . 4/3 . 6/5 ..... 200/199
CMR 14 < A < 20
Cho A=-2/1.-4/3.-6/5.....-200/199
cm 14<A<20
Cho A=\(\frac{2}{1}.\frac{4}{3}.\frac{6}{5}...\frac{200}{199}CMR:14< A< 20\)
Cho A=-2/1*-4/3*-6/5*...*-200/199
C/m:a,A>14
b,A<20
Cho A=\(-\dfrac{2}{1}.\dfrac{-4}{3}.\dfrac{-6}{5}.....\dfrac{-200}{199}\)
CM :
a>14 và A<20
a) -5/9 . 4/13+ -5/9. 9/13+2 và 5/9 ( 2 và 5/9 là hỗn số)
b) (-2)^3. -1/24+( 4/3- 1 và 5/6) : 3/14
c) 200 - (-100) -100+ (-20)
d) 15/34 +7/21 +19/34 -5/15 +3/7
e) (1-1/2) . (1-1/3). (1-1/4).....(1-1/1012)
g) (1/2+1/3-1/4) : 7/24
h) 15^20 . 9^10/ 27^12.25^10
CMR: \(14< \frac{2}{1}.\frac{4}{3}.\frac{6}{5}....\frac{200}{199}< 20\)
a,2/3 + 4/-5 x 20/16
b,(1/3+4/6).(2/7+9/14)
c,(2/3 - 3/4).(1/2- -3/5) help mik với
a,2/3 + 4/-5 x 20/16 =-1/3
b,(1/3+4/6).(2/7+9/14)=13/14
c,(2/3 - 3/4).(1/2- -3/5)=-11/120
a,2/3 + 4/-5 x 20/16
=2/3-1
=-1/3
b,(1/3+4/6).(2/7+9/14)
=1.13/14
=13/14
c,(2/3 - 3/4).(1/2- -3/5)
=-1/12.-1/10
=1/120
a) \(\dfrac{2}{3}+\dfrac{4}{-5}\times\dfrac{20}{16}\)\(=\dfrac{2}{3}+\dfrac{-4}{5}\times\dfrac{5}{4}\)\(=\dfrac{2}{3}+\left(-1\right)=-\dfrac{1}{3}\)
b) \(\left(\dfrac{1}{3}+\dfrac{4}{6}\right)\cdot\left(\dfrac{2}{7}+\dfrac{9}{14}\right)\)\(=1\cdot\dfrac{13}{14}=\dfrac{13}{14}\)
c) \(\left(\dfrac{2}{3}-\dfrac{3}{4}\right)\cdot\left(\dfrac{1}{2}-\dfrac{-3}{5}\right)\)\(=-\dfrac{1}{12}\cdot\dfrac{11}{10}=-\dfrac{11}{120}\)
1 tính
a,( 17/20+19/21). 31/20 (17/20+19/21). (-31/20)
b, 3/4.15/2+15/8.(-3) + 199/200
c, (199/200+201/202+2015/2014). (1/2+2/3+ -7/6)
d, a(b+1/5) -a ( 6/5 + b ) với a= 2015/2015 ; b= 2000
tính tổng
B= 7-7 mu 4 + 7 mu 4 -........+7 mu 301
A = 1 + 5 mũ 2 + 5 mu 4 + 5 mu 6 +.....+5 mu 200
tính
A= 1/7+1/7mu 2 + 1/7 mu 3+......+1/7mu 100
B=-4/5+4/5 mu 2 - 4/5 mu 3 + ....+4/5mu 200
tính A=25 mũ 8 + 25 mũ 4 + 25 mu 20 +......+25 mu 4 +1 / 25 mu 20 + 25 mu 28 + 25 mu 26 +.....= 25 mu 2 +1
7 × 3 mu x + 20 × 3 mu x = 3 mu 25