`@` `\text {Ans}`

`\downarrow`

`1.`

\(\left(-4xy\right)\cdot\left(2xy^2-3x^2y\right)\)

`=`\(\left(-4xy\right)\left(2xy^2\right)+\left(-4xy\right)\left(-3x^2y\right)\)

`=`\(-8\left(x\cdot x\right)\left(y\cdot y^2\right)+12\left(x\cdot x^2\right)\left(y\cdot y\right)\)

`=`\(-8x^2y^3+12x^3y^2\)

`2.`

\(\left(-5x\right)\left(3x^3+7x^2-x\right)\)

`=`\(\left(-5x\right)\left(3x^3\right)+\left(-5x\right)\left(7x^2\right)+\left(-5x\right)\left(-x\right)\)

`=`\(-15x^4-35x^3+5x^2\)

`3.`

\(\left(3x-2\right)\left(4x+5\right)-6x\left(2x-1\right)\)

`=`\(3x\left(4x+5\right)-2\left(4x+5\right)-12x^2+6x\)

`=`\(12x^2+15x-8x-10-12x^2+6x\)

`=`\(\left(12x^2-12x^2\right)+\left(15x-8x+6x\right)-10\)

`=`\(13x-10\)

`4.`

\(2x^2\left(x^2-7x+9\right)\)

`=`\(2x^2\cdot x^2+2x^2\cdot\left(-7x\right)+2x^2\cdot9\)

`=`\(2x^4-14x^3+18x^2\)

`5.`

\(\left(3x-5\right)\left(x^2-5x+7\right)\)

`=`\(3x\left(x^2-5x+7\right)-5\left(x^2-5x+7\right)\)

`=`\(3x^3-15x^2+21x-5x^2+25x-35\)

`=`\(3x^3-20x^2+46x-35\)

1: =1/8*9/4=9/32

2: =8/27*243/32=9/4

3: =(5/4*4/5)^5*(4/5)^2=16/25

4: \(=\left(-\dfrac{5}{6}\cdot\dfrac{6}{5}\right)^2\cdot\left(\dfrac{6}{5}\right)^2=\dfrac{36}{25}\)

5: \(=\left(-\dfrac{4}{3}\right)^3\cdot\left(\dfrac{3}{4}\right)^{10}=\left(-1\right)\left(\dfrac{3}{4}\right)^7=-\left(\dfrac{3}{4}\right)^7\)

6: \(=\left(\dfrac{1}{3}\cdot\dfrac{-9}{2}\right)^4\left(-\dfrac{9}{2}\right)^2=\left(-\dfrac{3}{2}\right)^4\cdot\dfrac{81}{4}=\dfrac{9}{4}\cdot\dfrac{81}{4}=\dfrac{729}{16}\)

8: =(0,2*5)^4*5^2=25

10: =-0,5^5*2^10

=-0,5^5*2^5*2^5

=-32

13: =(0,5*2)^2*2^2=4

1) \(\sqrt{1\dfrac{9}{16}}=\sqrt{\dfrac{25}{16}}=\dfrac{5}{4}\)

2) \(\dfrac{\sqrt{12.5}}{0.5}=\sqrt{\dfrac{12.5}{0.25}}=5\sqrt{2}\)

3) \(\sqrt{\dfrac{25}{64}}=\dfrac{5}{8}\)

4) \(\dfrac{\sqrt{230}}{\sqrt{2.3}}=\sqrt{\dfrac{230}{2.3}}=\sqrt{100}=10\)

5) \(\left(\sqrt{\dfrac{2}{3}}+\sqrt{\dfrac{50}{3}}-\sqrt{24}\right)\cdot\sqrt{6}\)

\(=\left(\dfrac{\sqrt{2}}{\sqrt{3}}+\dfrac{5\sqrt{2}}{\sqrt{3}}-2\sqrt{6}\right)\cdot\sqrt{6}\)

\(=\left(\dfrac{6\sqrt{2}}{\sqrt{3}}-2\sqrt{6}\right)\cdot\sqrt{6}\)

\(=0\cdot\sqrt{6}=0\)

1: \(23+\left(-13\right)+\left(-50\right)\)

\(=23-13-50\)

=10-50

=-40

2: \(-5+15+\left(-123\right)\)

\(=\left(-5+15\right)-123\)

=10-123

=-113

3: \(5871:\left\{928-\left[\left(-82+247\right)\right]\right\}\cdot5\)

\(=5871-\left\{928+82-247\right\}\cdot5\)

\(=5871-763\cdot5=5871-3815=2056\)

4: \(40-\left(4\cdot5^2-3\cdot2^3\right)\)

\(=40-4\cdot5^2+3\cdot2^3\)

\(=40-4\cdot25+3\cdot8\)

=40-100+24

=64-100

=-36

5: \(6^2\cdot5-7^2+149\)

\(=36\cdot5-49+149\)

\(=180+149-49\)

=180+100

=280

6: \(-210:\left[16+3\cdot\left(6+3\cdot2^2\right)\right]+\left(-2022\right)\)

\(=-210:\left[16+3\cdot\left(6+3\cdot4\right)\right]+\left(-2022\right)\)

\(=-210:\left[16+3\cdot18\right]+\left(-2022\right)\)

\(=-210:70-2022\)

=-3-2022

=-2025

7: \(5\cdot2^3+7^{11}:7^9-2023^0\cdot1^8\)

\(=5\cdot8+7^2-1\)

=40+49-1

=39+49

=88

8: \(400:\left\{5\cdot\left[360-\left(290+2\cdot5^2\right)\right]\right\}\)

\(=400:\left\{5\cdot\left[360-290-2\cdot25\right]\right\}\)

\(=400:\left\{5\cdot20\right\}\)

\(=\dfrac{400}{100}=4\)

9: \(75-\left(3\cdot5^2\right)-4\cdot5^3\)

\(=75-3\cdot25-4\cdot5^3\)

=-4*125

=-500

viết đề lại ko hiểu

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Bây h đăng câu hỏi khác đi

Kiểu vt tách ra á

\(\frac{5}{8}+\frac{15}{16}:\frac{3}{8}\times\frac{3}{4}=\frac{5}{8}+\frac{15}{8}=\frac{5}{2}.\)

\(\frac{9}{6}-\frac{1}{3}:\frac{1}{2}+\frac{5}{12}=\frac{3}{2}-\frac{2}{3}+\frac{5}{12}=\frac{5}{4}\)

Đề như z ak bn?

Chọn C

6 x 9 - 2 x 6 + 8 x 3 : 2 x 3

= 6 x 9 : 2 x 3 + - 2 x 6 : 2 x 3 + 8 x 3 : 2 x 3

=  3 x 6 - x 3 + 4