DẤU '' . '' LÀ DẤU NHÂN

*\(\left(45-25\right).\left(-11\right)+29.\left(-3-17\right)\)

\(=20.\left(-11\right)+29.\left(-20\right)\)

\(=-220+\left(-580\right)\)

\(=-800\)

*\(\left(-37\right).\left(55-23\right)-55.\left(23-37\right)\)

\(=-37.32-55.\left(-14\right)\)

\(=-1184-\left(-770\right)\)

\(=-1184+770\)

\(=-414\)

*\(\left(-12\right).\left(-125\right).\left(-4\right)\)

\(=1500.\left(-4\right)\)

\(=-6000\)

*\(\left(-1\right).2.\left(-3\right).4.\left(-5\right)\)

\(=-2.\left(-12\right).\left(-5\right)\)

\(=24.\left(-5\right)\)

\(=-120\)

A) ( 45 - 25 ) . ( -11 ) + 29 . ( -3 - 17 ) 

=   20.  ( -11 ) + 29 .  (-20)

= -20.( -11  + 29)

=-20.18

= -260

B)

a. 15.27-3.5.17

=15.27-15.17

=15.(27-17)

=15.10

=150

\(a,3x-75=45+3.\left(-25\right)\)

\(3x-75=-30\)

\(3x=45\)

\(x=15\)

\(b,2.\left(-7\right)-11=6x+17\)

\(-14-11-17=6x\)

\(-42=6x\)

\(-7=x\Leftrightarrow x=-7\)

\(d,-4.|x-3|=-48\)

\(|x-3|=12\)

\(\Rightarrow\orbr{\begin{cases}x-3=12\\x-3=-12\end{cases}\Rightarrow\orbr{\begin{cases}x=15\\x=-9\end{cases}}}\)

a)48.45+55.48=(45+55).48=100.48=4800

b)57.37+57.23+57.40=57.(23+37+40)=57.100=5700

c)25.5.4.17.2=(25.4).(5.17.2)=100.170=17000

d)127.45+55.127-27.100=127.(45+55)-(27.100)=127.100-27.100=(127-27).100=100.100=10000

e)543+165+457+35=(543+457)+(165+35)=1000+200=1200

g)13.58.4+32.6.2+52.10=(52.58)+(52.32)+52.10=52.(58+32+10)=52.100=5200

h)25.5.4.17.2=(25.4).(17.2.5)=100.170=17000

k)(3737.43-4343.37):(2+4+6+...+100)=(37.101.43-43.101.37):(2+4+6+...+100)=0.(2+4+6+...+100)=0

i)1+5+9+...+29+33+37=(1+37)+(5+33)+...=190

a=4800

b=5700

c=17000

d=10000

e=1200

...

phần còn lại bạn tự làm nhé

a/ 48.45+48.55

=48.(45+55)

=48.100

=4800

các bài sau tương tự nhé

a, |-37| + (-|15|) = 37 - 15 = 12
b, (-|-32|) +|5| = -32 + 5 = -27
c, (-|-22|) + (-|16|) = -22 - 16 = -38
d, (-23) + 13 + (-17) + 57 = 30
e, 14 + 6 + (-9) + (-14) = -3
g, (-123) +|-13| + (-7) = -123 + 13 + (-7) = -117
h, |0| + |45| + (-|-455|) + |-796| = 0 + 45 - 455 + 796 = 386
 

a/ =15+37+52-37-17

=(15+52)-17+(37-37)

=67-17+0

=50

b/=38-42+14-25+27+15

=-4+14+27-25+15

=10+27-40

=37-40

=-3

c/=-21+32+12-32

=-21+12+32-32

=11+0

=11

d/=-12-21+23-23+21-10

=-33+0+11

=-22

e/=57-725-605+53

=-668-605+53

=-1273+53

=-1220

f/=55+45+15-15+55-45

=55+55+45-45+15-15

=110+0+0

=110

Trong sách bài tập toán đó bạn !!

a, 15.27 - 3.5.17

= 15.27 - 15. 17

= 15 . ( 27 - 17 )

​= 15 . 10

= 150

​b, 55 - 5 . ( 20 + 11 )

​= 55 - 100 . 55

​= 55 . ( 1 - 100 )

​= 55 . ( -99 )

= ...

a,15.27-3.5.17

=15.27-15.17

=15(27-17)

=15.10=150

b,55-5(20+11)

=5.11-5.20-5.11

=5(11-20-11)

=5.(-20)=-100

c,37(29-23)-29(37-23)

=37.29-37.23-29.37+29.23

=37.29-29.37-37.23+29.23

=0+(-37+29).23

=-8.23=-184

a 15.27-3.5.7=15.27-15.7=15.(27-7)=15.20=300

b 55-5(20+11)=55-5.20+5.11=55-100+55=55.2-100=10

c 37.(29-23)-29.(37-23)=37.29-37.23-29.37-29.23=37.(29-29)-23.(37-29)=0-23.8=0-184=(-184)

tick đúng mình nha làm ơn bạn đó bạn ko tick mình thì bạn sẽ xui cả năm

a, =15.27-15.7

=15.20=300

b,=5.11-5.20-5.11

=5(11-20-11)

=5(-20)=-100

c,=37.29-37.23-29.37+29.23

=37.29-29.37-37.23+29.23

=0+(-37+29).23

=-8.23=-184

A 15.27-15.7

=15.(27-7)

=15.20

=300

B 55-5.(20+11)

=55-5.31

=55-155

=-100

C)37.(29-23)-29.(37-23)

=37.6-29.14

=222-406

=-184