7: =-1+8=7

6: \(=-\left(8\cdot125\right)\cdot\left(2\cdot5\right)\cdot\left(25\cdot4\right)=-1000000\)

5: =-50+19+143+79-25-48

=-75+98+95

=23+95

=118

4: =37x9+17x9-35x9-35x11

=18+153-385

=-214

3: =187-23-20+180

=367-43

=324

4: \(=37\cdot9+17\cdot9-35\cdot9-35\cdot11=19\cdot9-385\)

\(=171-385=-214\)

5: =-50+19+143+79-25-48

=-75+94+95

=20+94

=114

3 ; 324

4 ; -214

5 ; 118

6 ; - 1 000 000

7 ; 7

học tốt

a: 14/5-7/5=7/5

b: 7/8-1/3+5/4

=21/24-8/24+30/24

=43/24

c; =7/6+5/6+2/15+13/15

=2+1

=3

d: =4*5/3*11=20/33

e: =2/9*1/6*1/4=2/9*1/24=1/108

2:
a: \(=\dfrac{3}{9}\cdot\dfrac{4}{4}\cdot\dfrac{5}{5}\cdot\dfrac{6}{6}\cdot\dfrac{7}{7}=\dfrac{1}{3}\)

b: \(=\dfrac{1}{6}\left(\dfrac{22}{3}-\dfrac{2}{3}\right)=\dfrac{10}{3}\cdot\dfrac{1}{6}=\dfrac{10}{18}=\dfrac{5}{9}\)

c; \(=\dfrac{1}{3}\left(9-\dfrac{2}{5}-\dfrac{3}{5}\right)=\dfrac{8}{3}\)

14/5-7/5=7/5 

7/8-1/3+5/4=13/24+5/4=43/24 

7/6+2/15+5/6+13/15=13/10+5/6+13/15=32/15+13/15=3

4/3*5/11=20/35

2/9:6*1/4=1/27*1/4=1/108

a)
\(\frac{1.2+2.4+3.6+4.8+5.10}{3.4+6.8+9.12+12.16+15.20}\)
\(\frac{2.3\left(1.2\right)+2.3\left(2.4\right)+2.3\left(3.6\right)+2.3\left(4.8\right)+2.3\left(5.10\right)}{3.4\left(3.4+6.8+9.12+12.16+15.20\right)}\)
\(=\frac{\left(3.4+6.8+9.12+12.16+15.20\right)}{2.3\left(3.4+6.8+9.12+12.16+15.20\right)}=\frac{1}{2.3}=\frac{1}{6}\)

 

\(\frac{2^{12}.3^5-4^6.81}{\left[\left(2^2.3\right)^6+8^4.3^5\right]}=\frac{2^{12}.3^5-\left(2^2\right)^6.3^4}{2^{12}.3^6+\left(2^3\right)^4.3^5}\)

\(=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6-2^{12}.3^5}=\frac{2^{12}\left(3^5-3^4\right)}{2^{12}\left(3^6-3^5\right)}\)

\(=\frac{3^4\left(3-1\right)}{3^5\left(3-1\right)}=\frac{1}{3}\)

Thanks

Bài làm: 

\(\frac{2^{12}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}=\frac{2^{12}.\left(3^5-3^4\right)}{2^{12}.\left(3^6+3^5\right)}\)

                                \(=\frac{3^5-3^4}{3^6+3^5}=\frac{3^4.\left(3-1\right)}{3^5.\left(3+1\right)}=\frac{2}{3.4}=\frac{1}{6}\)

Bài làm

  (-2)+4+(-6)+8+(-10)+12

=    2    +   2     +     2

= 2 x 3

= 6

# Chúc bạn học tốt #

Ta có : \(\left(-2\right)+4+\left(-6\right)+8+\left(-10\right)+12\)

        \(=2+2+2\)

        \(=2.3\)

        \(=6\)

\(\dfrac{10.4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}=\dfrac{5.2.2^{12}.3^{10}+3^9.2^9.2^3.3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)

\(=\dfrac{5.2^{13}.3^{10}+2^{12}.3^{10}.5}{2^{11}.3^{11}\left(2.3-1\right)}=\dfrac{2^{12}.3^{10}.5\left(2+1\right)}{2^{11}.3^{11}.5}\)

\(=\dfrac{2^{11}.2.3^{10}.5.3}{2^{11}.3^{10}.3.5}=2\)

\(\frac{\left(-4\right)^6.9^5-\left(-6\right)^9.120.1^{2015}}{8^4.3^{12}-6^{11}.2016^0}=\frac{\left(2^2\right)^6.\left(3^2\right)^5+\left(2.3\right)^9.2^3.3.5.1}{\left(2^3\right)^4.3^{12}-\left(2.3\right)^{11}.1}=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)

\(=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2.6}{3.5}=\frac{4}{5}\)

\(\frac{\left(-4\right)^6.9^5-\left(-6\right)^9.120.1^{2015}}{8^4.3^{12}-6^{11}.2016^0}=\frac{\left(-2\right)^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2.6}{3.5}=\frac{4}{5}\)

2.31.12+4.6.42+8.27.3=24.31+24.42+24.27=24.(31+42+27)=24.100=2400