thực hiện phép tính sau:
3/7x11/13-3/13x15/7x-17/7
Bài 1: Thực hiện phép tính
a) (45-25).(-11)+29.(-3-17)
b) (36-6).(-5)+21.(-17-3)
Bài 2: Tìm x, biết:
a) -4.(2x+9)-(-8x+3)-(x-13)=0 b) 7x.(2+x)-7x.(x+3)=0
Trả lời
Bài 1:
a)(45-25).(-11)+29.(-3-17)
=20.(-11)+29.(-20)
=20.(-11)+(-29).20
=20.[(-11)+(-29)]
=20.(-30)
=-600
b)(36-6).(-5)+21.(-17-3)
=30.(-5)+21.(-20)
=(-150)+(-420)
=-570
trả lời:
a,(45-25).(-11)+29.(-3-17)
=20.(-11)+29.(-20)
=20.(-11)+(-29).20
=20.[(-11)+(-29).20
=20.(-30)
=-600
học tốt
Bài 9. Không thực hiện phép tính, hãy cho biết tổng (hiệu) sau là số nguyên tố hay hợp số? Vì sao?
1) 2. 13. 17 + 35. 37. 39 2) 17. 19. 23 – 7. 11. 13 3) 12343 + 98762
a: =35/17-18/17-9/5+4/5
=1-1=0
b: =-7/19(3/17+8/11-1)
=7/19*18/187=126/3553
c: =26/15-11/15-17/3-6/13
=1-6/13-17/3
=7/13-17/3=-200/39
Thực hiện phép tính 31/17+ -5/13+ -8/3 -14/17
`31/17+(-5/13)+(-8/3)-14/17`
`=(31/17-14/17)-(5/13-8/3)`
`=17/17-(15/39-104/39)`
`=1-(-89/39)`
`=1+89/39`
`=39/39+89/39`
`=128/39`
Thực hiện phép tính(tính hợp lí nếu có thể)
4/5+(-5)/4 -1/3+2/5-5/6 2/3-5/7.14/25 (2/5-5/6):8/15-(-1)^2
-3/13+(-7)/17+(-5)/19+(-10)/13+24/17+(-14)/19
\(\dfrac{4}{5}\)+\(\dfrac{-5}{4}\)=\(\dfrac{0}{4}\)
\(\dfrac{-1}{3}\)+\(\dfrac{2}{5}-\dfrac{5}{6}\)=\(\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}\)=\(\dfrac{-23}{30}\)
\(\dfrac{2}{3}-\dfrac{5}{7}.\dfrac{14}{25}\)=\(\dfrac{2}{3}-\dfrac{2}{5}\)=\(\dfrac{10}{15}-\dfrac{6}{15}\)=\(\dfrac{4}{15}\)
a: \(=\dfrac{16-25}{20}=\dfrac{-9}{20}\)
b: \(=\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}=-\dfrac{23}{30}\)
c: \(=\dfrac{2}{3}-\dfrac{1}{5}\cdot2=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10-6}{15}=\dfrac{4}{15}\)
d: \(=\dfrac{12-25}{30}\cdot\dfrac{15}{8}-1=\dfrac{-13}{16}-1=\dfrac{-29}{16}\)
e: \(=\dfrac{-3}{13}-\dfrac{10}{13}-\dfrac{7}{17}+\dfrac{24}{17}-\dfrac{5}{19}-\dfrac{14}{19}=-1\)
thực hiện phép tính sau : 13/7 - (-3/11) + 6/42
Bài 1: Thực hiện phép tính:
1, 4/23 + 5/21 + 0,5 - 4/23 + 16/21
2, (1/3 + 12/67 + 13/41)-(79/67 - 28/41)
3, 12,5 x (-5/7)+1,5 x (-5/7)
4, 3/8x19 1/3- 3/8x33 1/3
5, 5/7x(-3/11)+5/7x(-8/11)+2 5/7
6, (-5/11:13/8-5/11:13/5)- giá trị tuyệt đối của -1/33
1: \(\dfrac{4}{23}+\dfrac{5}{21}+\dfrac{1}{2}-\dfrac{4}{23}+\dfrac{16}{21}\)
\(=1+\dfrac{1}{2}\)
\(=\dfrac{3}{2}\)
2: \(\left(\dfrac{1}{3}+\dfrac{12}{67}+\dfrac{13}{41}\right)-\left(\dfrac{79}{67}-\dfrac{28}{41}\right)\)
\(=\dfrac{1}{3}+\dfrac{12}{67}+\dfrac{13}{41}-\dfrac{79}{67}+\dfrac{28}{41}\)
\(=\dfrac{1}{3}\)
C1.thực hiện phép tính sau :
a,12-[25+(6+3)^2]
b,315-(8^6 : 8^4 - 12.3+7+7^3)
c, -81-(108)
d, -13-91
e,-85-(-17)
g, 63 . (-8)+(-63).92
h, (-18).9-9.18
HELPPPPPPPP♤♤♤♤
a)\(12-\left[25+\left(6+3\right)^2\right]\)
\(=12-\left[25+9^2\right]\)
\(=12-\left[25+81\right]\)
\(=12-106\)
\(=\left(-94\right)\)
b) \(315-\left(8^6\div8^4-12.3+7+7^3\right)\)
\(=316-\left(8^2-36+7+343\right)\)
\(=316-\left(64-43+343\right)\)
\(=316-\left(21+343\right)\)
\(=316-364\)
\(=\left(-48\right)\)
c) \(-81-108\)
\(=-\left(81+108\right)\)
\(=\left(-189\right)\)
d) \(-13-91\)
\(=-\left(13+91\right)\)
\(=\left(-104\right)\)
e)\(-85-\left(-17\right)\)
\(=-85+17\)
\(=-\left(85-17\right)\)
\(=\left(-68\right)\)
g) \(63.\left(-8\right)+\left(-63\right).92\)
\(=63.\left(-8\right)+63.\left(-92\right)\)
\(=63.\left[\left(-8\right)+\left(-92\right)\right]\)
\(=63.\left(-100\right)\)
\(=\left(-6300\right)\)
Thực hiện phép tính: -1/8 + -5/3 -6/35× -49/54 6/5 - -4/3 31/17+ -5/13 +-8/13 -14/17
a: =-3/24-40/24
=-43/24
b: \(=\dfrac{6}{54}\cdot\dfrac{49}{35}=\dfrac{1}{9}\cdot\dfrac{7}{5}=\dfrac{7}{45}\)
c: \(=\dfrac{6}{5}+\dfrac{4}{3}=\dfrac{18+20}{15}=\dfrac{38}{15}\)
d: \(=\dfrac{31}{17}-\dfrac{14}{17}-\dfrac{5}{13}-\dfrac{8}{13}=1-1=0\)