`a)=45xx4xx2xx0,5`

`=180xx1=180`

`b)0,86xx8xx15xx1,25`

`=0,86xx15xx8xx1,25`

`=12,9xx10=129`

`c)=7,3xx(6,17+3,9)`

`=7,3xx10,07=73,511`

`d)=6,15xx(3/4+1/4)`

`=6,15xx1=6,15`

\(=3,5\times\left(2+5+3\right)\)

\(=3,5\times10=35\)

3,5 : 0,5 + 3,5 : 0,2 + 3 x 3,5

= 3,5 x 2 + 3,5 x 5 + 3 x 3,5

= 3,5 x (2 + 5 + 3)

= 3,5 x 10

= 35

a) Đề sai

b) Vì |x + 2,8| \(\ge\)0 \(\forall\)x

=> |x + 2,8| - 3,5 \(\ge\)-3,5 \(\forall\)x

Dấu " = " xảy ra khi và chỉ khi |x + 2,8| = 0 => x = -2,8

Vậy B_min = -3,5 khi x = -2,8

3,5 \(\times\) \(x\) - 1,8 - 1,2 = 0,5

3,5 \(\times\) \(x\) - (1,8 + 1,2) = 0,5

3,5 \(\times\) \(x\) - 3 = 0,5

3,5 \(\times\) \(x\)      = 0,5 + 3

3,5 \(\times\) \(x\)     =  3,5

          \(x\)     = 3,5 : 3,5

          \(x\)     = 1

x : 3,5 = 6 : 0,5

x : 3,5 = 12

x = 12 x 3,5

x = 42

x: 3,5 = 6 : 0,5

X: 3,5 = 12

X = 12 x 3,5

X= 42

Tick cho tớ với cậu ơi

Ta có ; A = 0,5 + |x - 3,5| 

Mà: |x - 3,5| \(\ge0\forall x\)

Nên : A = 0,5 + |x - 3,5| \(\ge0,5\forall x\)

Vậy A_min = 0,5 ; dấu "=" xảy ra khi và chỉ khi x = 3,5

Ta có : \(\left|x-3.5\right|\ge0\forall x\)

\(\Rightarrow\left|x-3.5\right|+0.5\ge0.5\forall x\)

Vậy \(Min_A=0.5\) khi \(x-3.5=0\Rightarrow x=3.5\)

\(A=\left|x-3,5\right|-0,5\)

\(\left|x-3,5\right|\ge0\forall x\)

\(A=\left|x-3,5\right|+0,5\ge0,5\)

Dấu "=" xảy ra khi:

\(\left|x-3,5\right|=0\Rightarrow x=3,5\)

6: \(9,5\times4,7+9,5\times4,3+9,5\)

\(=9,5\times\left(4,7+4,3+1\right)\)

\(=9,5\times10=95\)

5: \(32\times1,25\times2,5+0,476+0,524\)

\(=80\times1,25+1\)

=100+1

=101

4: \(3,5\times0,5+3,5\times0,125+3,5\times22,5\times4\)

=3,5x(90+0,5+0,125)

=3,5x90,625

=317,1875

3: \(32\times1,25\times2,5+\frac{54}{10}\times8,7+5,4\times3,3-10,8\)

\(=40\times2,5+5,4\times8,7+5,4\times3,3-5,4\times2\)

=100+5,4x(8,7+3,3-2)

=100+5,4x10

=100+54

=154

2: \(15,25\times0,5+15,25\times0,25+15,25\times0,125+15,25\times6\)

=15,25x(0,5+0,25+0,125+6)

=15,25x6,875

=104,84375

1: 2020x0,56+0,34x6060+8080x0,85+2020x5,02

=2020x0,56+2020x1,02+2020x3,4+2020x5,02

=2020x(0,56+1,02+3,4+5,02)

=2020x10

=20200

a, 2,5 x 16,27 x 4 + 7,3

\(=\left(2,5\times4\right)\times16,27+7,3\)

\(=10\times16,27+7,3\)

\(=162,7+7,3\)

\(=170\)

b, 0,25 x 1,25 x 8 x 4 x 0,5

\(=\left(0,25\times4\right)\times\left(1,25\times8\right)\times0,5\)

\(=1\times10\times0,5\)

\(=5\)

c, 500 x 3,26 x 0,02 : 0,5

\(=\left(500\times0,02\right)\times3,26\div0,5\)

\(=10\times3,26\times\frac{10}{5}\)

\(=3,26\times20\)

\(=65,2\)

d, 32,4 x 6,24 + 3,66 x 32,4 + 0,5

\(=32.4\times\left(3,66+6,24\right)+0,5\)

\(=32,4\times9,9+0,5\)

\(=320,76+0,5\)

\(=321,26\)

e, 17,2 x 9,55 + 9,45 x 17,2 + 17,2