A =( -8/19) . 25/34 . -17/5 . 19/-27
a) 25. 69 + 31. 25 – 150;
b) 198 : [130 – (27 – 19 )2] + 20210 ;
c) 520 : (515.15 + 515.10).
d) 27– (15 – 31) – (– 2 + 21+ 5)
e) 47 – (23 + 17) – (– 17 + 47)
f) 34 – [(–12) + 34] – (49 + 12) g) 72 – (15 – 14 + 72) + 52
a: =25x100-150=2500-150=2350
c: \(=520:\left\{515\cdot25\right\}\)
=104/2575
a 12 – 34 b 23 – 47 c 31 – 23 d 9 – 5 e 4 – 15 25 f 23 13 17 57 g 4 . 9 6 . 12 – 7 h 14 6 19 14 19 i 56 – 8. 27 7 j 8 5 . 2 – 3 6 k 4 . 3 125 . 25 8 l 9 6 . 3 – 4 7 m 45. 18 – 15 – 18. 45 – 15
Tách từng câu ra giùm, như này ai giải nổi:)))))
bài 1
a. 5/18 + 8/19 - 7/21 + ( -10/36 + 11/19 + 1/3) - 5/8
b.1/13 + ( -5/18 - 1/13 + 12/17 ) - ( 12/17 - 5/18 + 7/5 )
c.15/14 - (17/23 - 80/87 + 5/4)+(17/23 - 15/14 + 1/4 )
d.1/25 - 4/27 + ( -23/27 + -1/25 - 5/43 ) + 5/43 - 4/7
bài 2
a. x +1/3 = 3/4
b. x - 2/5 = 5/7
c. -x - 2/3 = -6/7
d. 4/7 - x = 1/3
e. x+ 5/2 = -3/2
f. x + 5/6 = -1/12
GIÚP MÌNH VỚI Ạ MÌNH CẢM ƠN TRƯỚC
Bài 1:
a; \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{7}{21}\) + (- \(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{1}{3}\) -\(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{10}{36}\)) + (\(\dfrac{8}{19}\) + \(\dfrac{11}{19}\)) - (\(\dfrac{1}{3}\) - \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{5}{18}\)) + \(\dfrac{19}{19}\) - 0 - \(\dfrac{5}{8}\)
= 0 + 1 - \(\dfrac{5}{8}\)
= \(\dfrac{3}{8}\)
b; \(\dfrac{1}{13}\) + (\(\dfrac{-5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\)) - (\(\dfrac{12}{17}\) - \(\dfrac{5}{18}\) + \(\dfrac{7}{5}\))
= \(\dfrac{1}{13}\) - \(\dfrac{5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{12}{17}\) + \(\dfrac{5}{18}\) - \(\dfrac{7}{5}\)
= (\(\dfrac{1}{13}\) - \(\dfrac{1}{13}\)) + (\(\dfrac{12}{17}\) - \(\dfrac{12}{17}\)) + (-\(\dfrac{5}{18}\) + \(\dfrac{5}{18}\)) - \(\dfrac{7}{5}\)
= 0 + 0 + 0 - \(\dfrac{7}{5}\)
= - \(\dfrac{7}{5}\)
Bài 1 c;
\(\dfrac{15}{14}\) - (\(\dfrac{17}{23}\) - \(\dfrac{80}{87}\) + \(\dfrac{5}{4}\)) + (\(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\))
= \(\dfrac{15}{14}\) - \(\dfrac{17}{23}\) + \(\dfrac{80}{87}\) - \(\dfrac{5}{4}\) + \(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\)
= (\(\dfrac{15}{14}-\dfrac{15}{14}\)) + (\(-\dfrac{17}{23}+\dfrac{17}{23}\)) - (\(\dfrac{5}{4}\) - \(\dfrac{1}{4}\)) + \(\dfrac{80}{87}\)
= 0 + 0 - 1 + \(\dfrac{80}{87}\)
= - \(\dfrac{7}{87}\)
Bài 1 d;
\(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) + (-\(\dfrac{23}{27}\) + \(\dfrac{-1}{25}\) - \(\dfrac{5}{43}\)) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) - \(\dfrac{23}{27}\) - \(\dfrac{1}{25}\) - \(\dfrac{5}{43}\) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= (\(\dfrac{1}{25}\) - \(\dfrac{1}{25}\)) - (\(\dfrac{4}{27}\) + \(\dfrac{23}{27}\)) - (\(\dfrac{5}{43}\) - \(\dfrac{5}{43}\)) - \(\dfrac{4}{7}\)
= 0 - 1 - 0 - \(\dfrac{4}{7}\)
= \(\dfrac{-11}{7}\)
số nguyên:
15 - ( -15 + 2)=
(-14) - (17 - 8)=
15 - ( 21- 7)=
34 + (-15) - 17=
(-34) + ( -12) + 18=
27 - 15 - 19=
34 - ( -15) +8=
-37 + 13 - 25=
40 - 17 + ( -25)=
16 + (-15 ) - 18=
15 - 14 - 13=
-27 + 15 -17=
34 - 71=
28 - 125=
13 + ( -27)=
14 - (-34)=
28 - (-16)=
-15 -8 =
-27 -34=
-25 - (-18)=
46 - 25 - (-25)=
-37 - (-24)=
46 - (-15)=
-26 - 6 + 7 =
15 - (-15 + 2) = 15 + 13 = 28
(-14) - (17 - 8) = -14 - 9 = -23
15 - (21- 7) = 15 - 14 = 1
34 + (-15) - 17 = 19 - 17 = 2
(-34) + (-12) + 18 = -46 + 18 = -28
27 - 15 - 19 = 12 - 19 = -7
34 - (-15) + 8 = 49 + 8 = 57
-37 + 13 - 25 = -24 - 25 = -49
40 - 17 + (-25) = 23 + (-25) = -2
16 + (-15) - 18 = 1 - 18 = -17
15 - 14 - 13 = 1 - 13 = -12
-27 + 15 - 17 = -12 - 17 = -29
34 - 71 = -37
28 - 125 = -97
13 + (-27) = -14
14 - (-34) = 48
28 - (-16) = 44
-15 - 8 = -23
-27 - 34 = -61
-25 - (-18) = -7
46 - 25 - (-25) = 21 + 25 = 46
-37 - (-24) = -13
46 - (-15) = 61
-26 - 6 + 7 = -32 + 7 = -25
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37=
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37
=(1+37)x37:2
=703
1) Tính giá trị các biểu thức :
a) C = 5/18 + 8/19 - 7/21 + ( -10/36 + 11/19 + 1/3) - 5/8
b) F = 15/14 - ( 17/23 - 80/87 + 5/4 ) + ( 17/23 - 15/14 + 1/4 )
c) G = 1/25 - 4/27 + ( -23/27 + -1/25 - 5/43 ) + 5/43 - 4/7
a) Ta có:
C = 5/18 + 8/19 - 7/21 + (-10/36 + 11/19 + 1/3) - 5/8
C = 5/18 + 8/19 - 1/3 - 5/18 + 11/19 + 1/3 - 5/8
C = (5/18 - 5/18) + (8/19 + 11/19) - (1/3 - 1/3) - 5/8
C = 1 - 5/8
c = 3/8
b) F = 15/14 - (17/23 - 80/87 + 5/4) + (17/23 - 15/14 + 1/4)
F = 15/14 - 17/23 + 80/87 - 5/4 + 17/23 - 15/14 + 1/4
F = (15/14 - 15/14) - (17/23 - 17/23) + 80/87 - (5/4 - 1/4)
F = 80/87 - 1
F = -7/87
c) G = 1/25 - 4/27 + (-23/27 + -1/25 - 5/43) + 5/43 - 4/7
G = 1/25 - 4/27 - 23/27 - 1/25 - 5/43 + 5/43 - 4/7
G = (1/25 - 1/25) - (4/27 + 23/27) - (5/43 - 5/43) - 4/7
G = -1 - 4/7 = -11/7
1)tính
a)-17+(-19)+25=
b)-26+(-25)-18=
c)35-(-19)-19-8=
d)1963-(-180)-1990
2)Tìm x thuộc z biết
a)x-(-18)=25+(-17)
b)x-28=-27-30
c)35-(-x)=27-17-(-8)
d)40+(-x)=35-(-27)
nhanh nha các bạn để mai mình đi học
1)tính
a)\(-17+\left(-19\right)+25\)
\(=-17-19+25\)
\(=-\left(17+19\right)+25\)
\(=-36+25\)
\(=-\left(36-25\right)\)
\(=-11\)
b)\(-26+\left(-25\right)-18\)
\(=-26-25-18\)
\(=-\left(26+25\right)-18\)
\(=-51-18\)
\(=-\left(51+18\right)\)
\(=-69\)
c)\(35-\left(-19\right)-19-8\)
\(=35+19-19-8\)
\(=35+\left(19-19\right)-8\)
\(=35+0-8\)
\(=35-8\)
\(=27\)
d)\(1963-\left(-180\right)-1990\)
\(=1963+180-1990\)
\(=2143-1990\)
\(=153\)
2)Tìm x thuộc z biết
a)\(x-\left(-18\right)=25+\left(-17\right)\)
\(\Leftrightarrow x+18=25-17\)
\(\Leftrightarrow x+18=8\)
\(\Leftrightarrow x=8-18\)
\(\Leftrightarrow x=-10\)
Vậy x=-10
b)\(x-28=-27-30\)
\(\Leftrightarrow x-28=-\left(27+30\right)\)
\(\Leftrightarrow x-28=-57\)
\(\Leftrightarrow x=-57+28\)
\(\Leftrightarrow x=-\left(57-28\right)\)
\(\Leftrightarrow x=-29\)
Vậy x=-29
c)\(35-\left(-x\right)=27-18-\left(-8\right)\)
\(\Leftrightarrow35+x=27-18+8\)
\(\Leftrightarrow35+x=9+8\)
\(\Leftrightarrow35+x=17\)
\(\Leftrightarrow x=17-35\)
\(\Leftrightarrow x=-18\)
Vậy x=-18
d)\(40+\left(-x\right)=35-\left(-27\right)\)
\(\Leftrightarrow40-x=35+27\)
\(\Leftrightarrow40-x=62\)
\(\Leftrightarrow x=40-62\)
\(\Leftrightarrow x=-22\)
Vậy x=-22
So sánh các tích sau hợp lý nhất:
P = (-21/34).(-13/27).7/9
Q = (-0,5).3/19.(-24/41).(-8/31)
M = -6/17.-5/17. ... .5/17.6/17
Ta có: P > 0 (vì âm nhân âm = dương)
Q < 0 (vì âm nhân âm nhân âm nhân dương = âm)
M = 0 (vì có thừa số 0/17)
Vậy Q<M<P
Câu 3: Trong các tập hợp sau đây, tập hợp nào chỉ toàn số nguyên tố.
A) A = {17; 19; 23; 27}
B) B = {19; 23; 25; 31}
C) C = {17; 19; 23; 31}
D) D = {17; 25; 27; 31}