AI GIÚP EM VỚI Ạ

\(#N\)

\(-\dfrac{11}{7}+\dfrac{13}{-2}+-\dfrac{6}{17}=-\dfrac{113}{14}+-\dfrac{6}{17}=-\dfrac{2005}{238}\)

\(\dfrac{13}{-8}+-\dfrac{7}{20}+\dfrac{3}{-8}=\left(-\dfrac{13}{8}+-\dfrac{3}{8}\right)+-\dfrac{7}{20}=-2+-\dfrac{7}{20}=-\dfrac{47}{20}\)

\(-\dfrac{4}{7}+\dfrac{11}{5}+\dfrac{1}{5}+-\dfrac{7}{3}=-\dfrac{4}{7}+\left(\dfrac{11}{5}+\dfrac{1}{5}\right)+-\dfrac{7}{3}=-\dfrac{4}{7}+\dfrac{12}{5}+-\dfrac{7}{3}=-\dfrac{53}{105}\)

a: \(\left(\frac45-\frac{13}{20}\right):\frac35\)

\(=\left(\frac{16}{20}-\frac{13}{20}\right)\cdot\frac53\)

\(=\frac{3}{20}\cdot\frac53=\frac{5}{20}=\frac14\)

b: \(197-13\cdot8+768\)

=197-104+768

=93+768

=861

c: \(20,7+1,47:7-23\%\cdot5\)

=20,7+0,21-1,15

=19,76

d: \(\frac{21}{77}\cdot\frac12+\frac{4}{11}\cdot\frac16+\frac{5}{11}\cdot\frac13\)

\(=\frac{3}{11}\cdot\frac12+\frac{2}{11}\cdot\frac13+\frac{5}{11}\cdot\frac13=\frac{3}{11}\cdot\frac12+\frac{7}{11}\cdot\frac13=\frac{3}{22}+\frac{7}{33}\)

\(=\frac{9}{66}+\frac{14}{66}=\frac{23}{66}\)

24 × 2 48         22 × 2 44         11 × 5 55         33 × 3 99         20 × 4 80

1) \(\left(+15\right)+\left(+17\right)=15+17=32\)

2) \(\left(-3\right)+\left(-7\right)=-3-7=-\left(3+7\right)=-10\)

3) \(\left(-25\right)+\left(+4\right)=-25+4=-\left(25-4\right)=-21\)

4) \(\left(-6\right)+\left(-54\right)=-6-54=-\left(6+54\right)=-60\)

5) \(\left(-15\right)+20=20-15=5\)

6) \(\left(-5\right)+8+7+5\)

\(=\left(-5+5\right)+\left(8+7\right)\)

\(=15\)

7) \(\left(-8\right)+\left(-11\right)+\left(-2\right)\)

\(=\left[\left(-8\right)+\left(-2\right)\right]+\left(-11\right)\)

\(=\left(-10\right)+\left(-11\right)\)

\(=-21\)

8) \(15+\left(-5\right)+\left(-14\right)+\left(-16\right)\)

\(=\left[15+\left(-5\right)\right]+\left[\left(-14\right)+\left(-16\right)\right]\)

\(=10+\left(-30\right)\)

\(=-20\)

9) \(\left(-20\right)+\left(-14\right)+3+\left(-86\right)\)

\(=\left[\left(-20\right)+3\right]+\left[\left(-14\right)+\left(-86\right)\right]\)

\(=\left(-17\right)+\left(-100\right)\)

\(=-117\)

10) \(\left(-136\right)+123+\left(-264\right)+\left(-83\right)+240\)

\(=\left[\left(-136\right)+\left(-264\right)\right]+\left[123+\left(-83\right)\right]+240\)

\(=\left(-400\right)+40+240\)

\(=\left(-360\right)+240\)

\(=-120\)

11) \(\left(-596\right)+2001+1999+\left(-404+189\right)\)

\(=\left(-596\right)+2001+1999-404+189\)

\(=\left[\left(-596\right)-404\right]+\left(2001+189\right)+1999\)

\(=\left(-1000\right)+2190+1999\)

\(=1190+1999\)

\(=3189\)

12) \(314+\left(-153\right)+64+121+\left(-247\right)+218\)

\(=\left(314+64+121\right)+\left[\left(-153\right)+\left(-247\right)\right]+218\)

\(=\left(378+121\right)+\left(-400\right)+218\)

\(=499-400+218\)

\(=99+218\)

\(=317\)

\(\text{#}Toru\)

coi lại câu a

1.1+1.1+1.1+1.1+1.1/1.1+1.1+9.3+6.8+.2

=33

a: Ta có: \(\left(2^2\cdot5\cdot3^3-5^2\cdot2^3+20\right)\cdot3^2-10\)

\(=\left(4\cdot5\cdot27-25\cdot8+20\right)\cdot9-10\)

\(=\left(540-200+20\right)\cdot9-10\)

\(=3240-10=3230\)

Dạ bài hay lắm ạ 

306 + 93 : 3 = 306 + 31

= 337

5 x 11 – 20 = 55 - 20

= 35