( -20 ) . 19/75 . 9/38 .2/3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(1)\frac{1}{3}.\frac{4}{5}+\frac{1}{3}.\frac{6}{5}-\frac{1}{3}\)
\(=\frac{1}{3}\left(\frac{4}{5}+\frac{6}{5}\right)\)
\(=\frac{1}{3}.2\)
\(=\frac{2}{3}\)
\(1)\)\(\frac{1}{3}.\frac{4}{5}+\frac{1}{3}.\frac{6}{5}-\frac{1}{3}\)
\(=\frac{1}{3}.\left(\frac{4}{5}+\frac{6}{5}-1\right)\)
\(=\frac{1}{3}.\left(\frac{4}{5}+\frac{6}{5}-\frac{5}{5}\right)\)
\(=\frac{1}{3}.1\)
\(=\frac{1}{3}\)
\(2)\)\(\frac{3}{7}.\frac{9}{26}-\frac{1}{14}.\frac{1}{13}\)
\(=\frac{1}{7}.\frac{27}{26}-\frac{1}{7}.\frac{1}{26}\)
\(=\left(\frac{27}{26}-\frac{1}{26}\right).\frac{1}{7}\)
\(=1.\frac{1}{7}\)
\(=\frac{1}{7}\)
\(3)\)\(15\left(\frac{1}{5}-\frac{7}{15}+\frac{17}{3}\right)\)
\(=3-7+85\)
\(=81\)
\(4)\)\(38\left(2\frac{1}{19}-5\frac{7}{38}\right)\)
\(=38\left(\frac{39}{19}-\frac{197}{38}\right)\)
\(=78-197\)
\(=-119\)
\(5)\)\(75\left(\frac{-4}{25}+7\frac{1}{15}-5\frac{7}{75}\right)\)
\(=75\left(\frac{-4}{25}+\frac{106}{15}-\frac{382}{75}\right)\)
\(=-12+530-382\)
\(=136\)
Ddaeng
(75*38-150*19):(1+2+3+...+2016)
=(75*38-75*38):(1+2+3+..+2016)
=0:(1+2+3+...+2016)
=0
bn tick cho mk nha
a) (38 - 60) + (20 - 38)
= 38 - 60 + 20 - 38
= (38 - 38) + (-60 + 20)
= 0 - 40
= -40
b) 75 - (20 + 75)
= 75 - 20 - 75
= (75 - 75) - 20
= 0 - 20
= -20
c) 32 + (60 - 32)
= 32 + 60 - 32
= (32 - 32) + 60
= 0 + 60
= 60
d) (81 - 36) - (81 - 36)
= 81 - 36 - 81 + 36
= (81 - 81) + (-36 + 36)
= 0 + 0
= 0
e) (2 + 4 + 6 + 8) - (1 + 3 + 5 + 7)
= 2 + 4 + 6 + 8 - 1 - 3 - 5 - 7
= (2 - 1) + (4 - 3) + (6 - 5) + (8 - 7)
= 1 + 1 + 1 + 1
= 4
f) (1 + 3 + 5 + 7 + ... + 99) - (2 + 4 + 6 + 8 + ... + 100)
= 1 + 3 + 5 + 7 + ... + 99 - 2 - 4 - 6 - 8 - ... - 100
= (1 - 2) + (3 - 4) + (5 - 6) + (7 - 8) + ... + (99 - 100)
= -1 - 1 - 1 - 1 - ... - 1 (50 chữ số 1)
= -50
A) 7/38 x 9/11 +7/38 x 4/11 -7/38 x 2/11
=7/38.(9/11+4/11-2/11)
=7/38
B) 5/31 x 21/25 + 5/31 x -7/10 - 5/31 x 9/20
=5/31.(21/25-7/10-9/20)
=5/31.(-31/100)
=-1/20
\(=\dfrac{2}{3}+\dfrac{81}{25}+\dfrac{8}{7}=\dfrac{38}{21}+\dfrac{81}{25}=\dfrac{2651}{525}\)
a) 3+2*x=15
2x=15-3
2x=12
x=12:2
x=6
Vậy x=6
b) 24-x=19
x=24-19
x=5
Vậy x=5
c) 29x-13=45
29x=45+13
29x=58
x=58:29
x=2
Vậy x=2
d) 5x-17=38
5x=38+17
5x=55
x=55:5
x=11
Vậy x=11
e) 50-2(x+1)=20
2(x+1)=50-20
2(x+1)=30
x+1+30/2
x+1=15
x=15-1=14
Vậy x=14
f)