ghi câu hỏi rõ bạn ơi

Bài 1 : Tính nhanh

a) 16.(38−2)−38(16−1)16.(38−2)−38(16−1)

b) (−41).(59+2)+59(41−2)(−41).(59+2)+59(41−2)

Bài 2 :

Tìm các số x ; y ; x biết rằng :

x + y = 2 ;  y + z = 3 ;  z + x = -5

Bài 3 : Tìm x ; y ∈∈ Z biết rằng :

( y + 1 ) . xy - 1 ) = 3

a) 16.(38−2)−38(16−1)

= 16.38 - 16.2 - 38.16 - 38.1

=-16.2 - 38.1

=-32-38

=-70

a) -4.2.6.25.(-7).5

= (2.5).(-4.25).(-7.6)

= 10.(-100).(-42)

= 42000

b) 16.(38 - 2) - 38.(16 - 1)

= 16.38 - 16.2 - 38.16 - 38

= -38 - 38

= -38.2

= -76.

c) Câu này đề không rõ nha.

a) 10-x-5=-5-7-11

=> 5 - x = -23

=> x = 28
b) |x| -3=0

=> |x| = 3

=> x = 3 hoặc x -3
c) ( 7-|x| ) .(2x-4)=0

=> 7 - |x| = 0 hoặc 2x - 4 = 0

=> |x| = 7 hoặc 2x = 4

=> x = 7 hoặc x = - 7 hoặc x = 2
c)2+3x=-15-19 

=> 2 + 3x = -34

=> 3x = 36

=> x = 12 
 

\(a,10-x-5=-5-7-11\)

\(10-x-5=-23\)

\(10-x=-18\)

\(x=28\)

\(b,|x|-3=0\)

\(|x|=3\)

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

a) \(47.69-31\left(-47\right)=47-69-\left(-31\right).47\)

\(=47.69+31.47=47.\left(69+31\right)=47.100=4700\)

b) \(16\left(38-2\right)-38\left(16-1\right)=16.38-16.2-38.16-\left(-38\right).1\)

\(=\left(16.38-38.16\right)-32+38=0-32+38=6\)

c) \(\left(-41\right)\left(59-2\right)+59\left(41-2\right)\) \(=\left(-41\right).59-\left[\left(-41\right).2\right]+59.41-59.2\)

\(=\left[\left(-41\right).59+59.41\right]-\left[\left(-49\right).2-51.2\right]=0-\left(-100\right).2=200\)

d) \(125.\left(-8\right)\left(-25\right)9.4.1000\div3=125.200.9.4.1000\div3\)

\(=\left(125.4\right)\left(9\div3\right)\left(200.1000\right)=500.3.200000=300000000\)

a) \(-524\cdot\left[23+\left(-45\right)\right]+524\cdot\left(-45+123\right)\)

\(=-524\cdot\left[\left(23-45\right)-\left(-45+123\right)\right]\)

\(=-524\cdot\left(23-45+45-123\right)\)

\(=-524\cdot-100\)

\(=52400\)

b) \(47\cdot69-31\cdot\left(-47\right)\)

\(=-47\cdot\left(-69-31\right)\)

\(=-47\cdot-100\)

\(=4700\)

c) \(16\left(38-2\right)-38\left(16-1\right)\)

\(=16\cdot38-16\cdot2-38\cdot16+38\)

\(=-16\cdot2+38\)

\(=-36+38\)

\(=2\)

d) \(\left(-41\right)\cdot\left(59+2\right)+59\cdot\left(41-2\right)\)

\(=-41\cdot59-41\cdot2+41\cdot59-2\cdot59\)

\(=-41\cdot2-2\cdot59\)

\(=-2\left(41+59\right)\)

\(=-2\cdot100\)

\(=-200\)

e) \(25\cdot\left(-8\right)\cdot\left(-25\right)\cdot9\cdot4\cdot100^0:3\)

\(=\left(-1000\right)\cdot\left(-25\right)\cdot9\cdot4\cdot1:3\)

\(=25000\cdot9\cdot4:3\)

\(=25000\cdot3\cdot4\)

\(=100000\cdot3\)

\(=300000\)

a: \(=4\cdot2\cdot6\cdot25\cdot7\cdot5\)

\(=\left(4\cdot25\right)\cdot\left(2\cdot5\right)\cdot\left(6\cdot7\right)\)

\(=42\cdot100\cdot10=42000\)

b: \(=16\cdot38-16\cdot2-38\cdot16+38\)

\(=-32+38=6\)

a)125.(-24)+24.225

=(-125).24+24.225

=24.[(-125)+225]

=24.100

=2400

       Các câu khác bạn làm tương tự nha

a ) \(125\times\left(-24\right)+24\times225\)

\(=24\left[\left(-125\right)+225\right]\)

\(=24\times100\)

\(=2400\)

b ) \(26\times\left(-125\right)-125\times\left(-36\right)\)

\(=125\left[\left(-26\right)-\left(-36\right)\right]\)

\(=125\times10\)

\(=1250\)

a,6

b,-200

c,1900

d,-900000

k mình nha 

mình cần gấp

 16 . ( 38 - 2 ) - 38 . ( 16 - 1 )

=16 . 38 - 2 .16 - 38 .16 - 1.38

=16.38.(2.16-1.38)

=608.(32-38)

=608.(-6)

=-3648

1 a, 16.38-16.2-38.16-38.1=608-32-608-38=-70 t

a)47.69-31.(-47)

=(47-47).69-31

=0.69-31

=690-31

=659

a. 47.69 - 31 .(-47)

=47 . 69 - (-31) .47

=47 . (69+31)

=47 . 100 = 4700