1) 20,22 : 0,5 + 20,22 : 0,125

= 20,22 x 2 + 20,22 x 8

= 20,22 x (2 + 8)

= 20,22 x 10

= 202,2

2) 3456 x 37 + 3456 x 19 + 3456 x 45 - 3456

= 3456 x 37 + 3456 x 19 + 3456 x 45 - 3456 x 1

= 3456 x (37 + 19 + 45 - 1)

= 3456 x 100

= 345600

\(M=\dfrac{1}{3456}.4\dfrac{1}{987}-3\dfrac{986}{987}.\dfrac{5}{3456}-6\dfrac{1}{3456}.\dfrac{1}{987}\)

Đặt \(\dfrac{1}{3456}=a\) và \(\dfrac{1}{987}=b\)

Chỉ cần thay những số bằng chữ đã đặt rồi rút gọn xong thế vào lại là ok

19629134

3456*5678-1234 = 19623168-1234=19621934                            

 = \(\left(\frac{341}{358}+\frac{17}{358}\right)+\left(\frac{2345}{3456}+\frac{1111}{3456}\right)\)

=\(\frac{358}{385}+\frac{3456}{3456}\)

=1+1=2

# Học tốt

= ( 341/358 +17/358 ) + ( 2345/3456+1111/3456  )

= 1 + 1

= 2

hok tốt

.....................

\(\frac{341}{358}+\frac{2345}{3456}+\frac{17}{358}+\frac{1111}{3456}\)

\(=\left(\frac{341}{358}+\frac{17}{358}\right)+\left(\frac{2345}{3456}+\frac{1111}{3456}\right)\)

\(=\frac{358}{358}+\frac{3456}{3456}\)

\(=1+1\)

\(=2\)

567 nha

567 nhé

567 nhé bạn

3:

a: -5x-16=-46

=>-5x=-46+16=-30

=>5x=30

=>\(x=\dfrac{30}{5}=6\)

b: -80-(-16-x)=20

=>\(-x-16=-80-20=-100\)

=>x+16=100

=>x=100-16=84

2:

a: \(\left(45-3456\right)+3456\)

\(=45+3456-3456\)

=45

b: \(\left(77+22-75\right)-\left(-25-78-13\right)\)

\(=77+13+22+78-75+25\)

\(=90+100-50\)

=140

c: \(-25\cdot63-25\cdot37\)

\(=-25\left(63+37\right)\)

\(=-25\cdot100=-2500\)

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