-20-(25-11+8)+(25-8+20)
Thực hiện phép tính bằng cách hợp lí :
a,-20 - (25 -11 +8) + (25 + 8 +20)
b,79.89 - 79.(-11) - 100.79
a,-20 - (25 -11 +8) + (25 + 8 +20)
= -20 - 25 + 11 - 8 + 25 + 8 + 20
= 11
b,79.89 - 79.(-11) - 100.79
= 79( 89 + 11 -100)
= 79 ( 100 - 100)
= 79 . 0
= 0
hok tốt!!
1) 15 - 98 + 91 - 75 + 98 - 91 - 13
2) 5 - ( 4 - 7 + 12 ) + ( 4 - 7 + 12 ) - 10
3) 20 - ( 25 - 98 + 12 ) + ( 25 - 98 - 72 )
4) - ( 17 - 4 + 13 + | -17 | + 13 )
5) | -16 | - ( 5 - 8 + 7) - ( - 5 ) - 8
6) -20 + ( 3 - 16 + 7 ) - ( 3 - 16 + 7 )
7) 32 - ( 5 - 8 + 32 ) + ( 5 - 8 + 6 )
8) -20 - ( 25 - 11 + 8 ) + ( 25 - 8 + 20 )
1)-73
2)-5
3)-64
4)-56
5)9
6)-20
7)6
8)-2
Tick nha
đăng tùng câu một thui bạn
bạn làm thế chắc tụi mk xỉu gần hết
97/20 - ( 25/8 - 221/200 )< x < 91/10 - (137/20 - 11/4)
phần mik gửi vừa nãy là vt nhầm , nên mik gửi lại
97/20 x ( 25/8 - 221/200 )< x < 91/10 x (137/20 + 11/4)
Đề bài : \(\dfrac{97}{20}\times\left(\dfrac{25}{8}-\dfrac{221}{200}\right)< x< \dfrac{91}{10}\times\left(\dfrac{137}{20}+\dfrac{11}{4}\right)\)
\(\dfrac{97}{20}\times\left(\dfrac{25}{8}-\dfrac{221}{200}\right)=\dfrac{97}{20}\times\dfrac{101}{50}=\dfrac{9797}{1000}\)
\(\dfrac{91}{10}\times\left(\dfrac{137}{20}+\dfrac{11}{4}\right)=\dfrac{91}{10}\times\dfrac{48}{5}=\dfrac{2184}{25}=\dfrac{2184\times40}{25\times40}=\dfrac{87360}{1000}\)
\(\Rightarrow\dfrac{9797}{1000}< x< \dfrac{87360}{1000}\)
Vậy \(x\in\left(\dfrac{9797}{1000};\dfrac{87360}{1000}\right)\)
22/25 x 5/11 - 33/25 : 11/5 + 58/11
8 3/11 - (3 5/7 - 7 8/11 )
1/5 + 7/5 : x = -3/20
5/6x + 325% = 3/2x -30,75
\(\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}:\frac{11}{5}+\frac{58}{11}\)
\(=\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}\times\frac{5}{11}+\frac{58}{11}\)
\(=\frac{5}{11}\times\left(\frac{22}{25}+\frac{33}{25}\right)+\frac{58}{11}\)
\(=\frac{5}{11}\times\frac{11}{5}+\frac{58}{11}\)
\(=1+\frac{58}{11}\)
\(=\frac{11}{11}+\frac{58}{11}\)
\(=\frac{69}{11}\)
\(8\frac{3}{11}-\left(3\frac{5}{7}-7\frac{8}{11}\right)\)
\(=\frac{91}{11}-\left(\frac{26}{7}-\frac{85}{11}\right)\)
\(=\frac{91}{11}-\frac{26}{7}+\frac{85}{11}\)
\(=\frac{91}{11}+\frac{85}{11}-\frac{26}{7}\)
\(=16-\frac{26}{7}\)
\(=\frac{86}{7}\)
\(\frac{5}{6}x+325\%=\frac{3}{2}x-30,75\)
\(=>\frac{5}{6}x+3,25=\frac{3}{2}x-30,75\)
\(=>\frac{5}{6}x-\frac{3}{2}x=-30,75-3,25\)
\(=>\frac{-2}{3}x=-34\)
\(=>x=-34:\left(-\frac{2}{3}\right)\)
\(=>x=-34.\left(\frac{3}{-2}\right)\)
\(=>x=51\)
bỏ dấu ngoặc rồi tính
a. 271 – [(-43) + 271 – (-17)]
b. (38 – 29 + 43) – (43 + 38)
c. -20 – (25 – 11 - 8) + (25 – 8 + 20)
a)271+43-271-17=26
b)38-29+43-43-38=-29
c)-20-25+11+8+25-8+20=11
học tốt
Điền dấu thích hợp vào chỗ chấm
9/14 ... 11/14 4/25 ... 4/23 5/6 ... 7/8 1 ... 14/15
8/9 ... 24/27 20/19 ... 20/27 8/7 ... 9/8 1 ...15/14
9/14 .<.. 11/14 4/25 .<.. 4/23 5/6 ..<. 7/8 1 ..>. 14/15
8/9 ..=. 24/27 20/19 ..>. 20/27 8/7 .>.. 9/8 1 .<..15/14
\(\dfrac{9}{14}< \dfrac{11}{14};\dfrac{8}{9}=\dfrac{24}{27}\)
\(\dfrac{4}{25}< \dfrac{4}{23};\dfrac{20}{19}>\dfrac{20}{27}\)
\(\dfrac{5}{6}< \dfrac{7}{8};\dfrac{8}{7}>\dfrac{9}{8}\)
\(1>\dfrac{14}{15};1< \dfrac{15}{14}\)
9/14 .<.. 11/14 4/25 .<.. 4/23 5/6 ..<. 7/8 1 ..>. 14/15
8/9 ..=. 24/27 20/19 ..>. 20/27 8/7 .>.. 9/8 1 .<..15/14
tính
5/5×8+6/8×11+6/11×14+.............+6/20×23
1994/9×11+1994/11×13+.......+1994/25×27
a,(100.5^7+5^11:25):(5.5^13:25^2)
b,(3^12+3^11):3^10
c,(2^43+2^4):(2^20+1)
d,(2^22+2^24+2^25):(2^18+2^19+2^20)
e,7.3^9+3^10+51.3^8