A) -1/39+-1/52
B) -6/9+-12/16
C) -2/5--3/11
D) -34/37 *74/-85
E) -5/9:-7/18
-1/39 + -1/52
-6/9 + -12/16
-2/5 - -3/11 -34/37 - 74/-85
-5/9 : -7/18
Giúp tớ với!! 3h10 đi học rồi
\(\frac{-1}{39}+\frac{-1}{52}=\frac{-7}{156}\)
\(\frac{-6}{9}+\frac{12}{16}=\frac{-2}{3}+\frac{3}{4}=\frac{1}{12}\)
\(\frac{-2}{5}-\frac{-3}{11}-\frac{34}{37}-\frac{74}{-85}=\frac{-1215}{6919}\)
\(\frac{-5}{9}:\frac{-7}{18}=\frac{-5}{9}.\frac{-18}{7}=\frac{10}{7}\)
-1/39 + -1/52
-6/9 + -12/16
-2/5 - -3/11
-34/37 - 74/-85
-5/9 : -7/18
Giúp tớ với!! 3h10 đi học rồi
-1/39 + -1/52 = -7/156
-6/9 + -12/16 = -17/12
-2/5 - - 3/11 [ (-) + ( -) = +] = -2/5 + 3/11 = -7/55
-34/37 - 74/ -85 = -152/3145
-5/9 : -7/18 = 10/7
-7/156
-17/12
-7/55
-152/3145
10/7
1) tìm x
a) 2/5 . x + 1/3 = 1/5
b) 1/5 + 5/3 : x = 1/2
c) 4/9 - 5/3 . x = - 2
d) 5/7 : x - 3 = -2/7
2) Thực hiện các phép tính bằng hai cách ( mấy cái cách ở dưới là hỗn số)
a) 17 2/9 + 6 1/9
b) 34 15/37 + 3 12/37
c) 12 2/7 + 35 3/14
d) 28 9/5 + 22 7/10
e) 74 2/8 - 17 1/8
f) 36 7/4 - 16 1/2
g) 64 2/15 - 36 5/3
h) 75 1/8 - 29 5/16
3) Thực hiện các phép tính sau ( mấy cái cách ở dưới là hỗn số)
a) 2 3/4 . 3 6/5
b) 4 3/8 . 2 4/7
c) 4 3/8 . ( - 2 4/7 )
d) 6 7/8 : ( - 2 8/9 )
e) ( - 6 1/2 ) . ( -3 1/5 )
f) ( - 4 2/9 ) . ( - 5 1/2 )
g) 7 1/3 . 2
h) 3 6/5 : 2
1) tìm x
a) 2/5 . x + 1/3 = 1/5
b) 1/5 + 5/3 : x = 1/2
c) 4/9 - 5/3 . x = - 2
d) 5/7 : x - 3 = -2/7
2) Thực hiện các phép tính bằng hai cách ( mấy cái cách ở dưới là hỗn số)
a) 17 2/9 + 6 1/9
b) 34 15/37 + 3 12/37
c) 12 2/7 + 35 3/14
d) 28 9/5 + 22 7/10
e) 74 2/8 - 17 1/8
f) 36 7/4 - 16 1/2
g) 64 2/15 - 36 5/3
h) 75 1/8 - 29 5/16
3) Thực hiện các phép tính sau ( mấy cái cách ở dưới là hỗn số)
a) 2 3/4 . 3 6/5
b) 4 3/8 . 2 4/7
c) 4 3/8 . ( - 2 4/7 )
d) 6 7/8 : ( - 2 8/9 )
e) ( - 6 1/2 ) . ( -3 1/5 )
f) ( - 4 2/9 ) . ( - 5 1/2 )
g) 7 1/3 . 2
h) 3 6/5 : 2
Bài 1:
a) Ta có: \(\dfrac{2}{5}\cdot x+\dfrac{1}{3}=\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{2}{5}\cdot x=\dfrac{1}{5}-\dfrac{1}{3}=\dfrac{-2}{15}\)
\(\Leftrightarrow x=\dfrac{-2}{15}:\dfrac{2}{5}=\dfrac{-2}{15}\cdot\dfrac{5}{2}\)
hay \(x=-\dfrac{1}{3}\)
Vậy: \(x=-\dfrac{1}{3}\)
b) Ta có: \(\dfrac{1}{5}+\dfrac{5}{3}:x=\dfrac{1}{2}\)
\(\Leftrightarrow\dfrac{5}{3}:x=\dfrac{1}{2}-\dfrac{1}{5}=\dfrac{3}{10}\)
\(\Leftrightarrow x=\dfrac{5}{3}:\dfrac{3}{10}=\dfrac{5}{3}\cdot\dfrac{10}{3}\)
hay \(x=\dfrac{50}{9}\)
Vậy: \(x=\dfrac{50}{9}\)
c) Ta có: \(\dfrac{4}{9}-\dfrac{5}{3}\cdot x=-2\)
\(\Leftrightarrow\dfrac{5}{3}x=\dfrac{4}{9}+2=\dfrac{22}{9}\)
\(\Leftrightarrow x=\dfrac{22}{9}:\dfrac{5}{3}=\dfrac{22}{9}\cdot\dfrac{3}{5}\)
hay \(x=\dfrac{22}{15}\)
Vậy: \(x=\dfrac{22}{15}\)
d) Ta có: \(\dfrac{5}{7}:x-3=\dfrac{-2}{7}\)
\(\Leftrightarrow\dfrac{5}{7}:x=\dfrac{-2}{7}+3=\dfrac{19}{21}\)
\(\Leftrightarrow x=\dfrac{5}{7}:\dfrac{19}{21}=\dfrac{5}{7}\cdot\dfrac{21}{19}\)
hay \(x=\dfrac{15}{19}\)
Vậy:\(x=\dfrac{15}{19}\)
giup mik cau nay vs
-1/39+-1/52=
-6/9+-12/16=
-2/5--3/11=
-34/37x 74/-85=
-5/9:-7/18=
giup mik vs
\(\dfrac{-1}{39}+\dfrac{-1}{52}=\dfrac{-7}{156}\)
\(\dfrac{-6}{9}+\dfrac{-12}{16}=\dfrac{-17}{12}\)
\(\dfrac{-2}{5}-\dfrac{-3}{11}=\dfrac{-7}{55}\)
\(\dfrac{-34}{37}.\dfrac{74}{-85}=\dfrac{4}{5}\)
\(\dfrac{-5}{9}:\dfrac{-7}{18}=\dfrac{10}{7}\)
Chúc bạn học tốt!!!
a) \(\left(-\dfrac{1}{39}\right)+\left(-\dfrac{1}{52}\right)=\dfrac{-4-3}{156}=-\dfrac{7}{156}\)
b) \(\left(-\dfrac{6}{9}\right)+\left(-\dfrac{12}{16}\right)=-\dfrac{6}{9}-\dfrac{12}{16}=-\dfrac{17}{12}\)
c) \(-\dfrac{2}{5}-\left(-\dfrac{3}{11}\right)=-\dfrac{2}{5}+\dfrac{3}{11}=-\dfrac{7}{55}\)
d) \(\left(-\dfrac{34}{37}\right)\cdot\left(-\dfrac{74}{85}\right)=2\cdot\dfrac{2}{5}=\dfrac{4}{5}\)
e) \(\left(-\dfrac{5}{9}\right):\left(-\dfrac{7}{18}\right)=\dfrac{5}{9}\cdot\dfrac{18}{7}=5\cdot\dfrac{2}{7}=\dfrac{10}{7}\)
a) \(\dfrac{-1}{39}+\dfrac{-1}{52}\)
b) \(\dfrac{-6}{9}+\dfrac{-12}{16}\)
c) \(\dfrac{-2}{5}-\dfrac{-3}{11}\)
d) \(\dfrac{-34}{37}.\dfrac{74}{-85}\)
e) \(\dfrac{-5}{9}:\dfrac{-7}{18}\)
a) \(\dfrac{-1}{39}+\dfrac{-1}{52}=\dfrac{-4}{156}+\dfrac{-3}{156}=\dfrac{-7}{156}\)
b) \(\dfrac{-6}{9}+\dfrac{-12}{16}=\dfrac{-2}{3}+\dfrac{-3}{4}=\dfrac{-8}{12}+\dfrac{-9}{12}=\dfrac{-17}{12}\)
c) \(\dfrac{-2}{5}-\dfrac{-3}{11}=\dfrac{-22}{55}-\dfrac{-15}{55}=\dfrac{-7}{55}\)
d) \(\dfrac{-34}{37}.\dfrac{74}{-85}=\dfrac{4}{5}\)
e) \(\dfrac{-5}{9}:\dfrac{-7}{18}=\dfrac{-5}{9}.\dfrac{18}{-7}=\dfrac{10}{7}\)
Bài 1: a,(-34)/37×74/-85
B, -5/9÷-7/18
a) \(\frac{-34}{37}\)\(\times\frac{74}{-85}\)\(\frac{-34}{37}\times\frac{74}{-85}=\frac{-34\times74}{37\times\left(-85\right)}=\frac{-34\times2}{1\times\left(-85\right)}=\frac{34}{85}\)
b) \(\frac{-5}{9}:\frac{-7}{18}=\frac{-5}{9}\times\frac{-18}{7}=\frac{-4\times\left(-18\right)}{9\times7}=\frac{-4\times\left(-2\right)}{1\times7}=\frac{8}{7}\)
Tính:
a,\(\frac{-1}{39}+\frac{-1}{52}\) b,\(\frac{-6}{9}+\frac{-12}{16}\) c,\(\frac{-2}{5}-\frac{-3}{11}\) d,\(\frac{-34}{37}\cdot\frac{74}{-85}\) e,\(\frac{-5}{9}:\frac{-7}{18}\)
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+149+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39*100