\(3\sqrt{2}-\sqrt{8}+\sqrt{50}-4\sqrt{32}=3\sqrt{2}-2\sqrt{2}+5\sqrt{2}-16\sqrt{2}=-10\sqrt{2}.\)

a) 2√18 - 4√50 + 3√32

= 6√2 - 20√2 + 12√2

= -2√2

b) √(√8 - 4)² + √8

= 4 - √8 + √8

= 4

c) √(14 - 6√5) + √(6 + 2√5)

= √(3 - √5)² + √(√5 + 1)²

= 3 - √5 + √5 + 1

= 4

\(a,2\sqrt{18}-4\sqrt{50}+3\sqrt{32}\\ =6\sqrt{2}-20\sqrt{2}+12\sqrt{2}=-2\sqrt{2}\\ b,\sqrt{\left(\sqrt{8}-4\right)^2}+\sqrt{8}\\ =4-\sqrt{8}+\sqrt{8}\\ =4\\ c,\sqrt{14-6\sqrt{5}}+\sqrt{6+2\sqrt{5}}\\ =\sqrt{\left(3+\sqrt{5}\right)^2}+\sqrt{\left(\sqrt{5}+1\right)^2}=3+\sqrt{5}+\sqrt{5}+1\\ =4+2\sqrt{5}\)

a) \(79.2^3+21.2^3\)

\(=\left(79+21\right).2^3=100.8\)

= 800

b) \(2.\left(6.4^2-85:5\right)\)

\(=2.\left(96-17\right)=2.79\)

= 158

c) (- 5) . 8 . (- 2) . 3

= \(\left[\left(-5\right).\left(-2\right)\right].\left(8.3\right)\)

= 10 . 24 = 240

d) 200 + 32 - (50 + 32)

= 200 + 32 - 50 - 32 (quy tắc mở ngoặc đổi dấu)

= 200 + (32 - 32) - 50

= 200 - 50 = 150

e) 3 . \(\left(-2\right)^2\) + 4 . (- 5) + 20

= 3 . 4 + 4 .(- 5) + 20

= 4 . (-2) + 20

= - 8 + 20 = 12

Chúc học tốt!!

a) 79. 2³ + 21 . 2³

= 79 . 8 + 21 . 8

= ( 79 + 21 ) . 8

= 100 . 8

= 800

b) 2. ( 6 . 4² - 85 : 5 )

= 2 . ( 6 . 16 - 17 )

= 2 . ( 96 - 17 )

= 2 . 17

= 34

c) (-5) . 8 . (-2) . 30

= (-40) . (-2) . 3

= 80 . 3

= 240

d) 200 + 32 - ( 50 + 32 )

= 232 - 82

= 150

e) 3. (-2)² + 4. (-5) + 20

= 3. (-4) + 4 . ( -5) + 20

= (-12 ) + (-20) + 20

= (-12) + 0

= (-12)

\(a,79.2^3+21.2^3.\)

\(=\left(79+21\right)2^3.\)

\(=100.2^3=100.8=800.\)

\(b,2\left(6.4^2-85:5\right).\)

\(=2\left(6.16-17\right).\)

\(=2\left(96-17\right).\)

\(=2.81=162.\)

\(c,\left(-5\right).8.\left(-2\right).3.\)

\(=\left[\left(-5\right).\left(-2\right)\right].\left(8.3\right).\)

\(=10.24=240.\)

\(d,200+32-\left(50+32\right).\)

\(=200+32-50-32.\)

\(=\left(200-50\right)+\left(32-32\right).\)

\(=150+0=150.\)

\(e,3.\left(-2\right)^2+4.\left(-5\right)+20.\)

\(=3.4+4.\left(-5\right)+20.\)

\(=\left[3+\left(-5\right)\right]4+20.\)

\(=\left(-2\right).4+20.\)

\(=\left(-8\right)+20=12.\)

~ Học tốt ~

6: \(=3\cdot2\sqrt{3}-4\cdot3\sqrt{3}+5\cdot4\sqrt{3}=14\sqrt{3}\)

7: \(=2\sqrt{3}+5\sqrt{3}-4\sqrt{3}=3\sqrt{3}\)

8: \(=2\cdot4\sqrt{2}+4\cdot2\sqrt{2}-5\cdot3\sqrt{2}=\sqrt{2}\)

9: \(=3\cdot2\sqrt{5}-2\cdot3\sqrt{5}+4\sqrt{5}=4\sqrt{5}\)

10: \(=2\cdot2\sqrt{6}-2\cdot3\sqrt{6}+3\sqrt{6}-5\sqrt{6}=-4\sqrt{6}\)

5) (-19).(-13)+13.(-29)

=19.13+13.(-29)

=13.[19+(-29)]

=13.(-10)

=-130

10) 3.(-2)²+4.(-5)+20

=3.4-20+20

=12+0

=12

\(\sqrt{32}+\sqrt{50}-2\sqrt{8}+\dfrac{1}{3}\sqrt{18}\)

\(=\sqrt{4^2\cdot2}+\sqrt{5^2\cdot2}-2\cdot2\sqrt{2}+\dfrac{1}{3}\cdot\sqrt{3^2\cdot2}\)

\(=4\sqrt{2}+5\sqrt{2}-4\sqrt{2}+\dfrac{1}{3}\cdot3\sqrt{2}\)

\(=\left(4\sqrt{2}-4\sqrt{2}\right)+5\sqrt{2}+\sqrt{2}\)

\(=5\sqrt{2}+\sqrt{2}\)

\(=6\sqrt{2}\)

66x17+32x17+17x2

=(66+32+2)x17

=100x17

=1700

32x20+32x29+32x11+60x68

=32x(20+29+11+68)

=32x100

=3200

12x25x2+24x25+3x50x8

=25x(24+24+48) (mik tách 50 ra là 2x25 rùi nhân 3x2x8 ra 48 còn 24 ở đầu thì mik lấy 12x2=24 nha )

=25x100

=2500

M=2+4+6+...+98+100

có 4-2=2

6-4=2

100-98=2

có số liền trước kém số liền sau 2 đơn vị 

SSH là:

(100-2):2+1=50 (số )

Tổng M là : 

(100+2)x50 :2= 2550

vậy M =2550

66 x 17 + 32 x 17 + 17 x 2

= 17 ( 66 + 32 + 2 )

= 17 x 100 = 1700

32 x 20 + 32 x 29 + 32 x 11 + 60 x 68

= 32 x ( 20 + 29 + 11 ) + 60 x 68

= 32 x 60 + 60 x 68

= 60 x ( 32 + 68 )

= 60 x 100 = 6000

12 x 25 x 2 + 24 x 25 + 3 x 50 x 8

= 24 x 25  + 24 x 25 + 48 x 25 

= 25 ( 24 + 24 + 48 )

= 25 x 96

66 x 17 + 32 x 17 + 17 x 2 = 17 x (66 + 32 + 2)

                                           = 17 x 100 

                                            = 1700

32 x 20 + 32 x 29 + 32 x 11 + 60 x 68 =  32 x ( 20 + 29 + 11 ) + 60 x 68 

                                                             = 32 x 60 + 60 x 68

                                                             = 60 x ( 32 + 68)

                                                             = 60 x 100

                                                             = 6000

12 x 25 x 2 + 24 x 25 + 3 x 50 x 8 = 12 x 50 + 12 x 2 x 25 + 3 x 50 x 8

                                                      = 12 x 50 + 12 x 50 + 3 x 50 x 8 

                                                      = 12 x 50 + 12 x 50 + 24 x 50

                                                      = (12 + 12 + 24) x 50

                                                      = 48 x 50

                                                      = 24 x 2 x 50

                                                      = 24 x 100

                                                      = 2400

Số số hạng : (100 - 2) : 2 + 1 = 50 (số)

Tổng : (2 + 100) x 50 : 2 = 2550

Vậy M = 2550

Chúc bạn hok tốt nha!

a: \(20-\left[30-\left(5-1\right)^2\right]\)

\(=20-\left[30-4^2\right]\)

\(=20-14=6\)

b: \(71+\dfrac{50}{5+3\left(57-6\cdot7\right)}\)

\(=71+\dfrac{50}{5+3\cdot\left(57-42\right)}\)

\(=71+\dfrac{50}{5+3\cdot15}=71+\dfrac{50}{50}=72\)

c: \(4\cdot\left\{270:\left[50-\left(2^5+45:5\right)\right]\right\}\)

\(=4\cdot\left\{270:\left[50-32-9\right]\right\}\)

\(=4\cdot\left\{\dfrac{270}{50-41}\right\}=4\cdot\dfrac{270}{9}=4\cdot30=120\)

d: \(411-\left[\dfrac{\left(107+3\right)}{5}-2^2\right]\)

\(=411-\left[\dfrac{110}{5}-4\right]\)

=410-22+4

=410-18

=392

e: \(450-5\left[3^2\left(7^5:7^3-41\right)-12\right]+18\)

\(=450-5\left[9\cdot\left(7^2-41\right)-12\right]+18\)

\(=450-5\cdot\left[9\cdot8-12\right]+18\)

=468-5*60

=468-300

=168

f:

\(102-150:\left[18-2\cdot\left(10-8\right)^2\right]+1018^0\)

\(=102-150:\left[18-2\cdot4\right]+1\)

\(=103-\dfrac{150}{18-8}=103-15=88\)

1.

\(\sqrt{50}-3\sqrt{8}+\sqrt{32}=5\sqrt{2}-6\sqrt{2}+4\sqrt{2}=3\sqrt{2}\)

2. 

a, ĐK: \(x\in R\)

\(pt\Leftrightarrow\sqrt{\left(x-2\right)^2}=1\)

\(\Leftrightarrow\left|x-2\right|=1\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)

b, ĐK: \(x\ge3\)

\(pt\Leftrightarrow\sqrt{x-3}\left(\sqrt{x}-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x-3}=0\\\sqrt{x}-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=1\left(l\right)\end{matrix}\right.\)