Ý bạn là mỗi phép tính phải thêm dấu và ....để kết quả bằng 6 phải không ạ

(1+1+1)×2=6

2+2+2=6

3×3⁰+3=6

(4+4+4)÷2=6

(5⁰+5⁰+5⁰)×2=6

6×6⁰×6⁰=6

7-7⁰×7⁰=6

8-(8⁰+8⁰)=6

(9⁰+9⁰+9⁰)×2=6

(10⁰+10⁰+10⁰)×2=6

a ) bằng 0.

b ) bằng 65.

a. (45-63+18) x (1+2+3+4+5+6+7+8+9)

= 0 x (1+2+3+4+5+6+7+8+9) = 0

b. 60-61+62-63+64-65+66-67+68-69+70

= 60 + (-61-69)+(62+68)+(-63-67)+(64+66)-65+70

= 60 + (-130)+130+(-130)+130-65-70

= 60 + (-130+130) + (-130+130)-65+70

= 60 - 65 + 70 = 65

(sai rồi)

Tính nhanh:

 1+2+3+4+5+6+7+8+9+10

=(1+9)+(2+8)+(3+7)+(4+6)+10+5

=  10  +  10  +  10   + 10  + 10+5

=             50   +   5

=    55

123*45+123*50+123*5

=  123*(45+50+5)

=   123 * 100

=   12300

K mk nha bn

1+2+3+4+5+6+7+8+9+10

= ( 1+10 ) + ( 2+9) + (3+8) + (4+7) + (5+6)

=     11    +      11   +   11    +   11  +    11

=11 x 5 

=55

123 x 45 + 123 x 50 + 123 x 5 

= 123 x ( 45 + 50 +5 )

= 123 x 100

=12300

hok tốt .

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 10 : 2 x 11 = 55

123 x 45 + 123 x 50 + 123 x 5 = 123x ( 45 + 50 + 5) = 123 x 100 = 12300

6 2/7  + 7 3/5 + 8 6/9 + 9 1/4 + 2/5 +  5/7 + 1/3  x 3/4 + 1967

= 44/7 + 38/5 + 78/9 + 37/4 + 2/5 + 5/7 + 1/3 + 1967

= ( 44/7 + 5/7 ) + ( 38/5 + 2/5 ) + ( 26/3 + 1/3 ) + ( 37/4 + 3/4 )  +1967

=  7 + 8 + 9 + 10  + 1967

= 15  + 9 + 10 + 1967

= 24 + 10 + 1967

= 34 + 1967 

= 2001

tính nhanh lớp 6 20 nhân 17-4 nhân 5 nhân 7

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

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

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

\(=499-400+218\)

\(=99+218\)

\(=317\)

\(\text{#}Toru\)

4: \(=\dfrac{2+3}{7}+\dfrac{1+6}{9}-\dfrac{5}{6}=\dfrac{5}{7}+\dfrac{7}{9}-\dfrac{5}{6}=\dfrac{83}{126}\)

5: \(=\dfrac{-5-2}{7}+\dfrac{3+1}{4}-\dfrac{1}{5}=-\dfrac{1}{5}\)

6: \(=\dfrac{-3-28}{31}+\dfrac{-6-1}{17}+\dfrac{1-5}{25}=-1-\dfrac{7}{17}-\dfrac{4}{25}=-\dfrac{668}{425}\)

4. \(\dfrac{2}{7}+\dfrac{1}{9}+\dfrac{3}{7}+\dfrac{5}{9}+\dfrac{-5}{6}\)

\(=\left(\dfrac{2}{7}+\dfrac{3}{7}\right)+\left(\dfrac{1}{9}+\dfrac{5}{9}\right)+\dfrac{-5}{6}\)

\(=\dfrac{5}{7}+\dfrac{2}{3}+\dfrac{-5}{6}\)

\(=\dfrac{30+28+\left(-35\right)}{42}=\dfrac{23}{42}\)
 

5. \(\dfrac{-5}{7}+\dfrac{3}{4}+\dfrac{-1}{5}+\dfrac{-2}{7}+\dfrac{1}{4}\)

\(=\left(\dfrac{-5}{7}+\dfrac{-2}{7}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\dfrac{-1}{5}\)

\(=\dfrac{-7}{7}+\dfrac{4}{4}+\dfrac{-1}{5}\)

\(=-1+1+\dfrac{-1}{5}\)

\(=-\dfrac{1}{5}\)
 

6. \(\dfrac{-3}{31}+\dfrac{-6}{17}+\dfrac{1}{25}+\dfrac{-28}{31}+\dfrac{-1}{17}+\dfrac{-1}{5}\)

\(=\left(\dfrac{-3}{31}+\dfrac{-28}{31}\right)+\left(\dfrac{-6}{17}+\dfrac{-1}{17}\right)+\dfrac{1}{25}+\dfrac{-1}{5}\)

\(=\dfrac{-31}{31}+\dfrac{-7}{17}+\dfrac{1}{25}+\dfrac{-1}{5}\)

\(=-1+\dfrac{-7}{17}+\dfrac{1}{25}+\dfrac{-1}{5}\)

\(=\dfrac{-425+\left(-175\right)+17+\left(-85\right)}{425}=\dfrac{-668}{425}\)