a) 135 + (-2) . 14 - 135 +28
b) -18 . 2 + 18 . (-6) + (-18) . 3
a) 135 + (-2) . 14 -135 + 28
b) -18 . 2 +18 . (-6) + (-18) . 3
Đáp án :
a) \(135+\left(-2\right).14-135+28\)
\(=135+\left(-28\right)-135+28\)
\(=135-28-135+28\)
\(=135-135+28-28=0\)
b) \(-18.2+18.\left(-6\right)+\left(-18\right).3\)
\(=18.\left(2+6+3\right)=18.11=198\)
a) \(135+\left(-2\right)\cdot14-135+28\)
\(=135+\left(-28\right)-135+28\)
\(=\left(135-135\right)+\left[\left(-28\right)+28\right]\)
\(=0+0\)
\(=0\)
b) \(-18\cdot2+18\cdot\left(-6\right)+\left(-18\right)\cdot3\)
\(=-18\cdot2+\left(-18\right).6+\left(-18\right).3\)
\(=-18\cdot\left(2+6+3\right)\)
\(=-18\cdot11\)
\(=-198\)
1) Rút gọn p/s:
a) 6*9 - 2*17 / 63*3 - 119
b) 2*3 + 4*6 + 14*21 / 3*5 + 6*10 + 21*35
c) 3*13 - 13*18 / 15*40 - 80
d) (-5)^3*40*4^3 / 135 * (-2)^14 * (-100)^0
e)18*34+(-18)*124 / -36 *17 +9*(-52)
a: \(=\dfrac{54-34}{189-119}=\dfrac{20}{70}=\dfrac{2}{7}\)
b: \(=\dfrac{6+6\cdot4+6\cdot49}{15+15\cdot4+15\cdot49}=\dfrac{6}{15}=\dfrac{2}{5}\)
c: \(=\dfrac{13\left(3-18\right)}{40\left(15-2\right)}=\dfrac{-15}{40}=-\dfrac{3}{8}\)
a)A = 9.(−2) a) 3 +12 : (34−28)
b) B = |−100|+(135−58)−(142−865)
c) C = 23.45+155.(−23) +230
d)D = 54.(46+18)−46(54−18)+5 2 .(−2\(^{\left(-2\right)^3}\)
a,tính tổng : \(S=\dfrac{27+4500+135+550+2}{2+4+6+...+14+16+18}\)
b, So sánh : \(A=\dfrac{2006^{2006}+1}{2006^{2007}+1}v\text{à }B=\dfrac{2006^{2005}+1}{2006^{2006}+1}\)
- Mình dùng cách lớp 8 để làm câu b được không :)?
- Tham khảo câu b:
https://olm.vn/hoi-dap/tim-kiem?q=+++++++++++A=2006%5E2005+1/2006%5E2006+1B=2006%5E2006+1/2006%5E2007+1so+s%C3%A1nh+A+v%C3%A0+B&id=520258
tính nhanh:
a,31.(-18)+31.(-81)-31
b,13.(23+22)-3.(17+28)
c,(-12).47+(-12).52+(-12)
d,-48+48.(-78)+48.(-21)
e,135.(171-123)-171.(135-123)
g,-(-2009+97)-74.(-18)+74.(-118)-2009-3
\(a,31.\left(-18\right)+31.\left(-81\right)-31\)
\(=31\left(-18-81-1\right)\)
\(=31\left(-100\right)\)
\(=-3100\)
\(b,13\left(23+22\right)-3\left(17+28\right)\)
\(=299+286-51-84\)
\(=450\)
Tính tổng: S = \(\dfrac{27+4500+135+550.2}{2+4+6+...+14+16+18}\)
\(S=\dfrac{27+4500+135+550.2}{2+4+6+...+14+16+18}\)
\(S=\dfrac{4527+135+1100}{\left(2+18\right).9.2}\)
\(S=\dfrac{4662+1100}{20.9.2}\)
\(S=\dfrac{5762}{90}\)
\(S=\dfrac{2881}{45}\)
`S=(27+4500+135+550.2)/(2+4+6+…+14+16+18)`
`S=(27+4500+135+1100)/((2+18)+(4+16)+…+(8+12)+10)`
`S=((27+135)+(4500+1100))/(20+20+…+20+10)` `(`Có `4` số hạng `20)`
`S=(162+5600)/(20.4+10)`
`S=5762/90`
`S=2881/45`
bài 3. bỏ dấu ngoặc rồi tính
( 18 + 29) + ( 158- 28 - 18) =
( 13 - 135 + 49 ) - ( 13 + 49)=
( 18+29 ) + ( 158-28-18)
=18+29+158-28-18
=29 + ( 18-18) + ( 158-28)
=29+0+130=159
(13-135+49)-(13+49)
=13-135+49-13-49
=(13-13)+(49-49)-135
=0+0+(-135)
=-135
Tính nhanh :
1> 31.(-18)+31.(-81)-31
2> (-12).47+(-12).52+(-12)
3> 13.(23+22)-3.(17+28)
4>-48+48.(-78)+48(-21)
5>135.(171-123)-171.(135-123)
6> -(-2009+97)-74.(-18)+74.(-118)-2009-3
Giải luôn bây giờ tớ tích luôn cho . Giải hết 6 câu cùng một lúc luôn nhé ! Giúp mình nhớ !
nhiều quá à
nhìn mk ko muốn làm
nhiều bài quá
chúc bn học gioi!
ahjhj
1> 31.(-18)+31.(-81)-31
=31(-18-81-1)
=31.-100
=-3100
1,Tính giá trị biểu thức
a, 13 . 17 - 256 : 16 + 14 : 7 - 1
b, 15 . 24 - 14 . 5 . (145 : 5 - 27)
c, 15 . 8 - (17 - 30 + 83) - 144 : 6
d,18 - 4 . (27 - 90 + 73) : 10
2,Tìm x
a, 315 - (135 - x)=215
b, x - 320 : 32 = 25 . 16
c, 3 . x - 2018 : 2 = 23
d, 280 - 9 . x - x = 80
e, 38 . x - 12 . x - x . 16 = 40
Giúp mình với nhé,mình đang cần gấp !!
2,
a) \(315-\left(135-x\right)=215\)
\(\Rightarrow135-x=315-215\)
\(\Rightarrow135-x=100\)
\(\Rightarrow x=135-100\)
\(\Rightarrow x=35\)
b) \(x-320:32=25\cdot16\)
\(\Rightarrow x-10=5^2\cdot4^2\)
\(\Rightarrow x-10=20^2\)
\(\Rightarrow x-10=400\)
\(\Rightarrow x=410\)
c) \(3\cdot x-2018:2=23\)
\(=3\cdot x-1009=23\)
\(\Rightarrow3\cdot x=1032\)
\(\Rightarrow x=1032:3\)
\(\Rightarrow x=344\)
d) \(280-9\cdot x-x=80\)
\(\Rightarrow280-x\cdot\left(9+1\right)=80\)
\(\Rightarrow280-10\cdot x=80\)
\(\Rightarrow10\cdot x=280-80\)
\(\Rightarrow10\cdot x=200\)
\(\Rightarrow x=20\)
e) \(38\cdot x-12\cdot x-x\cdot16=40\)
\(\Rightarrow x\cdot\left(38-12-16\right)=40\)
\(\Rightarrow x\cdot10=40\)
\(\Rightarrow x=40:10\)
\(\Rightarrow x=4\)