a.156.72+28.156=?
b.32.(-39)+16.(-22)=?
c.-1945-(567-1945)=?
d.x-2=-6?
e.-5x-(-3)=13?
f.15-(x-7)=-21?
g.3x+17=2?
h.|x-2|=3
i.-5<x<1?
k.|x|<3
1, 156.72+28.156
2, 32.(-39)+16.(-22)
3, -1945-(567-1945)
4, 184.33+67.184
5, 44.(-36)+22.(-28)
Mk đag cần gấp nhé.
1.
156.72+156.28
=156.(72+28)
=156.100
=15600
2.
32.(-39)+16.(-22)
=16.2.(-39)+16.(-22)
=16.[2.(-39)+(-22)]
=16.(-100)
=-1600
3.
-1945-(567-1945)
=-1945-567+1945
=-1945+1945-567
=0-567
=-567
4.
184.33+67.184
=184.(33.67)
=184.100
=18400
5.
44.(-36)+22.(-28)
=2.22.(-36)+22.(-28)
=22.[2.(-36)+(-28)]
=22.(-100)
=-2200
học tốt nhé
Bài 1: Tính hợp lí nhất
1, 2155– (174 + 2155) + (-68 + 174)
2, -25 . 72 + 25 . 21 – 49 . 25
3, 35(14 –23) – 23(14–35)
4, 8154– (674 + 8154) + (–98 + 674) 5, – 25 . 21 + 25 . 72 + 49 . 25
6, 27(13 – 16) – 16(13 – 27)
7, –1911 – (1234 – 1911)
8, 156.72 + 28.156
9, 32.( -39) + 16.( –22)
10, –1945 – ( 567– 1945)
11, 184.33 + 67.184
12, 44.( –36) + 22.( –28)
câu 1 = -68
câu 2 =-2500
câu 3=168
câu 4 =4571
câu 6=124
-1911-(1234-1911)
156.72+28.156
32.(-39)+16.(-22)
-1945-(567-1945)
184.33+67.184
44.(-36)+22.(-28)
Tính hợp lí nhất :
1/2155-(174+2155)+(-68+174)
2/-25.72+25.21-49.25
3/35(14-23)-23(14-35)
4/8154-(674+8154)+(-98+674)
5/-25.21+25.72+49.25
6/27(13-16)-16(13-27)
7/-1911-(1234-1911)
8/156.72+28.156
9/32.(-39)+16.(-22)
10/-1945-_567-1945
11/184.33+67.184
a2/44.(-36)+22.(-28)
Bài 1: Tính một cách hợp lý
6/ 27(13-16) - 16(13 - 27)
7/ -1911 - (1234 - 1991)
8/ 156.72 + 28 . 156
9/ 32 . (-39) + 16 . (-22)
10/ -1945 - (567 - 1945)
11/ 184. 33 + 67. 184
12/ 44.(-36) + 22 . (-28)
Bài 2:
a,x-2=-6-5x-16
b,-5x-[-3]-x=13-x
c,15-[x-7]=-21-x
d,3x+17=2+3x+15
e,x-45-[x-9]=-35-x
f,[-5]+x=15-x-2x
g,2x-[-17]=15
a)x-2=6-5x-16
6x= -8
x= -4/3
b)-5x-(-3)-x=13-x
-5x+3-x=13-x
-5x=10
x=-2
c)15-(x-7)=-21-x
15-x+7=-21-x
22=-21 ( vô lí)
x không có giá trị
D)3x+17=2+3x+15
17=17
x có vô số giá trị
e) x-45-(x-9)=-35-x
x-45-x+9=-35-x
-x=1
x=-1
f) -5+x=15-x-2x
4x=20
x=5
g) 2x-(-17) =15
2x+17=15
2x=-2
x=-1
Bài 1: Tính một cách hợp lí:
1) 2155 - ( 174 + 2155 ) + ( -68 + 174 ) 7) -1911 - ( 1234 - 1911 )
2) -25 . 72 + 25 . 21 - 49 . 25 8) 156 . 72 + 28 . 156
3) 35 . ( 14 - 23 ) - 23 . ( 14 - 35 ) 9) 32. ( -39 ) + 16 . ( -22 )
4) 8154 - ( 674 + 8154 ) + ( -98 + 674 ) 10) -1945 - ( 567 - 1945 )
5) -25 . 21 + 25 . 72 + 49 . 25 11) 184 . 33 + 67 . 184
6) 27 . ( 13 - 16 ) - 16 . ( 13 - 27) 12) 44 . ( -36 ) + 22 . ( -28 )
1) 2155-(174+2155)+(-68+174-7)-1911-(1234-1911)
=2155-174-2155+(-68)+174-7-1911-1234+1911
=(2155-2155)+(174-174)+(1911-1911)-(68+7+1234)
= 0 + 0 + 0 - 1309
= -1309
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
a. 2/3x-1/2=1/10
b. 39/7:x=13
c. (14/5x-50):2/3=51
d. (x+1/2)(2/3-2x)=0
e. 2/3x-1/2x=5/12
g. (x.44/7+3/7)11/5-3/7=-2
h. x.13/4+(-7/6)x-5/3=5/12
i.93/17:x+(-4/17):x+22/7:52/3=4/11
j. 17/2-|2x-3/4|=-7/4
k. (x+1/5)^2+17/25=26/25
l. -32/27-(3x-7/9)^3=-24/27
a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)
b) \(\dfrac{39}{7}:x=13\)
\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)
c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)
\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)
\(\dfrac{14}{5}x=34+50=84\)
\(x=\dfrac{84}{\dfrac{14}{5}}=30\)
d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)
e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)
\(\dfrac{1}{6}x=\dfrac{5}{12}\)
\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)
g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)
\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)
\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)
\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)
\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)
h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)
\(x=1\)
Mỏi tay woa bn làm nốt nha!!