\(\frac{1}{4}\times45+0,25\times35+\frac{25}{100}\times19+25\%\)

\(=0,25\times45+0,25\times35+0,25\times19+0,25\)

\(=0,25\times\left(45+35+19+1\right)\)

\(=0,25\times100=25\)

\(\frac{1}{4}\times45+0,25\times35+\frac{25}{100}\times19+25\%\)

\(=0,25\times45+0,25\times35+0,25\times19+0,25\times1\)

\(=0,25\times\left(45+35+19+1\right)\)

\(=0,25\times100\)

\(=25\)

lần sau bn vt dấu các phép tính ra nha, vt như nay khó đọc lắm ak

\(=0,25\times49+0,25+0,25\times31+0,25\times19\\ =0,25\times\left(49+1+31+19\right)\\ =0,25\times100\\ =25\)

`25%×49+25/100+1/4×31+0,25×19`

`=0,25×49+0,25+0,25×31+0,25×19`

`=0,25×(49+1+31+19)`

`=0,25×100`

`=25`

\(25\%\times49+\dfrac{25}{100}+\dfrac{1}{4}\times31+0,25\times19\)

\(=\dfrac{25}{100}\times49+\dfrac{25}{100}+\dfrac{1}{4}\times31+\dfrac{1}{4}\times19\)

\(=\dfrac{1}{4}\times49+\dfrac{1}{4}+\dfrac{1}{4}\times31+\dfrac{1}{4}\times19\)

\(=\dfrac{1}{4}\times\left(49+31+19\right)\)

\(=\dfrac{1}{4}\times100\)

\(=25\)

a,25/100 +19/22+19/35+3/4+3/22+16/35

=(19/22+3/22)+(19/35+16/35)+(25/100+3/4)

=   22/22 + 35/35 + ( 1/4 + 3/4)

= 22/22 + 35/35 + 4/4

= 1 + 1 + 1

= 3

b, 2/5 : 4/7 - 2/5 : 2/3

=(2/5 - 2/5) : (4/7 : 2/3)

= 0 : 6/7

=0

tất cả các số kia là đều phần hết

1) \(\frac{25}{100}+\frac{19}{22}+\frac{19}{35}+\frac{3}{4}+\frac{3}{22}+\frac{16}{35}\)

\(=\frac{1}{4}+\frac{19}{22}+\frac{19}{35}+\frac{3}{4}+\frac{3}{22}+\frac{16}{35}\)

\(=\left(\frac{1}{4}+\frac{3}{4}\right)+\left(\frac{19}{22}+\frac{3}{22}\right)+\left(\frac{19}{35}+\frac{16}{35}\right)\)

\(=1+1+1\)

\(=3\)

2) \(\frac{2}{5}:\frac{4}{7}-\frac{2}{5}:\frac{2}{3}\)

\(=\frac{2}{5}:\left(\frac{4}{7}-\frac{2}{3}\right)\)

\(=\frac{2}{5}:\frac{-2}{21}\)

\(=-\frac{21}{5}\)

=))

   \(\dfrac{25}{100}\) + \(\dfrac{1}{4}\) x 29 + 25% \(\times\) 30 + 0,25 \(\times\) 40

= 0,25+ 0,25 x 29 + 0,25 x 30 + 0,25 x 40

= 0,25 x ( 1 + 29 + 30 + 40)

= 0,25 x 100

= 25

 \dfrac{25}{100}10025​ + \dfrac{1}{4}41​ x 29 + 25% $\times$ 30 + 0,25 $\times$ 40

= 0,25+ 0,25 x 29 + 0,25 x 30 + 0,25 x 40

= 0,25 x ( 1 + 29 + 30 + 40)

= 0,25 x 100

= 25

1/\(\left(-12\right)\cdot46-12\cdot54=\left(-12\right)\cdot46+\left(-12\right)\cdot54\)

\(=\left(-12\right)\cdot\left(46+54\right)=\left(-12\right)\cdot100=-1200\)

2/\(3784+23-3785-15=3785+22-3785-15\)

\(=22-15=7\)

3/\(\left(-8\right)\cdot25\cdot\left(-2\right)\cdot4\cdot\left(-5\right)\cdot125\)

\(=\left[\left(-8\right)\cdot125\right]\cdot\left[25\cdot4\right]\cdot\left[\left(-5\right)\cdot\left(-2\right)\right]\)

\(=\left(-1000\right)\cdot100\cdot10=-1000000\)

4/\(19\cdot25+9\cdot95+19\cdot30=19\cdot\left(25+30\right)+9\cdot95\)

\(=19\cdot55+9\cdot95=95\cdot11+9\cdot95=95\cdot\left(11+9\right)=20\cdot95=1900\)

5/\(\left(-50+19+143\right)-\left(-79+25+48\right)\)

\(=\left(-50\right)+19+143+79-25-48\)

\(=118\)

6/\(\left(-25\right)\cdot\left(75-45\right)-75\cdot\left(45-25\right)\)

\(=\left(-25\right)\cdot30+\left(-25\right)\cdot3\cdot20\)

\(=\left(-25\right)\cdot\left(30+60\right)=\left(-25\right)\cdot90=-2250\)

7/\(\left(-37-17\right)\cdot\left(-9\right)+35\left(-9-11\right)\)

\(=\left(-54\right)\cdot\left(-9\right)+35\cdot\left(-20\right)\)

\(=486+\left(-700\right)=-214\)

8/\(\left(187-23\right)-\left(20-180\right)\)

\(=187-23-20+180=324\)

9/\(512\cdot2-128\cdot\left(-512\right)\)

\(=512\cdot2+128\cdot512=512\cdot\left(2+128\right)\)

\(=512\cdot130=66560\)

10/\(17\cdot\left(-25\right)+25\cdot21\)

\(=17\cdot\left(-25\right)-\left(-25\right)\cdot21=\left(-25\right)\cdot\left(17-21\right)\)

\(=\left(-25\right)\cdot\left(-4\right)=100\)

Chúc bạn học tốt.

25 + 25 > 49;

19 + 21 > 30;

45 + 45 = 100 – 10;

1) (-12).46-12.54

=12.(-46)-12.54

=12.(-46-54)

=12.(-100)=(-1200)

10) 17.(-25)+25.21

= (-17).25+25.21

=25.(-17+21)

=25.4=100

( Mik đọc lướt qua thì thấy hai bài này dễ nên làm, chứ mấy bài kia chưa suy nghĩ gì, bạn tự làm nốt nhé!)

2: \(=\left(3784-3785\right)+\left(23-15\right)=\left(-1\right)+8=7\)

3: \(=-8\cdot25\cdot2\cdot4\cdot5\cdot125\)

\(=-8\cdot125\cdot25\cdot4\cdot2\cdot5=-1000\cdot100\cdot10=-1000000\)

4: \(=19\left(25+9\cdot5+30\right)=19\cdot100=1900\)

5: \(=-50+19+143+79-25-48\)

\(=\left(-50-25+79\right)+143+19-48\)

=54+143-29

=143+25=168

6: \(=-25\cdot75+25\cdot45-75\cdot45+75\cdot25\)

\(=45\left(25-75\right)=45\cdot\left(-50\right)=-2250\)

7: \(=-54\cdot\left(-9\right)+35\cdot\left(-20\right)\)

\(=486-700=-214\)

8: \(=187-23-20+180=164+160=324\)

9: \(=512\left(2-128+128\right)=512\cdot2=1024\)