\(\dfrac{9}{14}+\dfrac{3}{19}+\dfrac{5}{14}=\left(\dfrac{9}{14}+\dfrac{5}{14}\right)+\dfrac{3}{19}=1+\dfrac{3}{19}=\dfrac{22}{19}\)
\(\dfrac{9}{14}+\dfrac{3}{19}+\dfrac{5}{14}=\left(\dfrac{9}{14}+\dfrac{5}{14}\right)+\dfrac{3}{19}=1+\dfrac{3}{19}=\dfrac{22}{19}\)
bài 1 tính
a) (3/7+-9/8)+(5/8+-6/14)
b) (-5/7+3/11)+(-11/14+14/-11)
c)(-4/5+2/3)+(-5/4+19/5)+(7/3.2)
d)9/16.13/4-9/4.5/16+9/16.17/4
A=(1/4*9 + 1/9*14 + 1/14*19 + ...+ 1/44*49)*1-3-5-7-..-49/89
Bài 1 : Tính một cách hợp lí
A = -3/7 + 14/23 + -14/17 +9/23 - 5/19
B= 5/9 . 7/13. 5/9 .9/13 . -5/13. 3/9
Giúp mình với!!!
a 12 – 34 b 23 – 47 c 31 – 23 d 9 – 5 e 4 – 15 25 f 23 13 17 57 g 4 . 9 6 . 12 – 7 h 14 6 19 14 19 i 56 – 8. 27 7 j 8 5 . 2 – 3 6 k 4 . 3 125 . 25 8 l 9 6 . 3 – 4 7 m 45. 18 – 15 – 18. 45 – 15
a,-8/3+7/5+-71/15<x<-13/7+19/14+-7/2
b,-19/6+-15/2+11/3<x<-5/4+19/12+-10/3
c,-6/7+3/35<x<-2/5+3/7
d,x=3/4+1/-12
e,x/14=1/7+-3/14
f,11/18+13/6=85/x
g,8/17+5/17<x/17<6/17+9/17
Tính:
a. 1-5+7-8+4-1+5-7+8
b. 12-14+9-3-14+9-3+14-19-9-12
c. 20-4+8-17+4-8-20+15
d. 13-98+91-75+98-91-13
Làm giúp mình rõ ràng nha, mình cần gấp cảm ơn các bạn
5×36^9×4^6-2×12^14×3^6÷5×2^28×3^19-7×2^29×3^18
12) 17 – 11 – 14 – (-39)
13) −127 - 18.( 5 - 6)
14) 100 + (+430) + 2145 + (-530)
15) (+12).13 + 13.(-22)
16) {[14 : (-2)] + 7} : 2012
17) 13 – 18 – (- 42) - 15
18) 369 – 4[(-5) + 4.(-8)]
19) (-12).(-13) +13.(-29)
20) 125 – 4[ 3 – 7.(-2) ]
21) (-14).9 – 13.(-9) chỉ em với
4, -5/6 - 26/5 . 1/13
5, (19/23 - 22/46) . 23/16
6, (3/4 . - 5/7) . (20/9 . - 14/15)