58 x 58 + 52 x 58 – 10

= 58 x (58 + 52 -10)

= 58 x 100

= 5800

a)2×4,8× 0,5 +4× 16× 0,25+ 20: 10× 0,5

=(2×0,5)×4,8+(4×0,25)×16+(2×0,5)

= 4,8               + 16                 +1

=21,8

b)12,5 × 3,14 ×8 +16 ×0,125 × 1,57

= 0,125×100×3,14×8+16×0,125×1,57

=(0,125×3,14×8+8×2×0,125×1,57)×100

=[0,125×3,14×8+8×0,125×(1,57×2)]×100

=[0,125×3,14×8+8×0,125×3,14]×100

= [(0,125×3,14×8)×2]×100

=6,28×100

=628

ko biet

1 và37,37

a, 

2 x 4 x 8 x 0,5 x 0,125 x 0,25 x (0,4321 + 0,5679)

= 2 x 4 x 8 : 2 : 8 : 4 x 1

= (2 : 2) x (4 : 4) x (8 : 8) x 1

= 1 x 1 x 1 x 1

= 1

đề nó bị dính nhau quá bn!

a: \(2\cdot4\cdot8\cdot0,5\cdot0,125\cdot0,25\cdot\left(0,4321+0,5679\right)\)

\(=\left(2\cdot0,5\right)\cdot\left(4\cdot0,25\right)\cdot\left(8\cdot0,125\right)\cdot1\)

\(=1\cdot1\cdot1\cdot1=1\)

b: \(3,7\cdot3,8+8,3\cdot3,7-0,4\cdot3,7\cdot5\)

\(=3.7\left(3,8+8,3\right)-3,7\cdot2\)

\(=3,7\cdot12,1-3,7\cdot2\)

\(=3,7\left(12,1-2\right)=3,7\cdot10,1=37,37\)

c: \(0,51:0,1+0,57:1,9+0,49:0,1-0,3\)

\(=0,51\cdot10+0,49\cdot10+0,57:1,9-0,3\)

\(=10\left(0,51+0,49\right)+0,3-0,3\)

\(=10\cdot1=10\)

\(\dfrac{1}{4}:0,25-\dfrac{1}{8}:0,125+\dfrac{1}{2}:0,5-\dfrac{1}{16}:0,0625\\ =0,25:0,25-0,125:0,125+0,5:0,5-0,0625:0,0625\\ =1-1+1-1\\ =0+1-1\\ =1-1\\ =0\)

1/4:1/4-1/8:1/8+1/2:1/2-1/16:1/16

=1-1+1-1 

=0

\(a)101\times0,75-0,75\)

\(=0,75\times(101-1)\)

\(=0,75\times100=75\)

___________________________________________

`b)10:0,5+4:0,25+8:0,125`

\(=10\times2+4\times4+8\times8\)

\(=5\times4+4\times4+4\times16\)

\(=4\times(5+4+16)\)

\(=4\times25=100\)

$a)101\times 0,75-0,75$

$=0,75\times (101-1)$

$=0,75\times 100=75$

___________________________________________

$b)10:0,5+4:0,25+8:0,125$

$=10\times 2+4\times 4+8\times 8$

$=5\times 4+4\times 4+4\times 16$

$=4\times (5+4+16)$

$=4\times 25=100$

\(\dfrac{1}{10}+\dfrac{2}{10}+\dfrac{3}{10}+\dfrac{4}{10}+\dfrac{5}{10}+\dfrac{6}{10}+\dfrac{7}{10}+\dfrac{8}{10}+\dfrac{9}{10}\)

\(=\left(\dfrac{1}{10}+\dfrac{9}{10}\right)+\left(\dfrac{2}{10}+\dfrac{8}{10}\right)+\left(\dfrac{3}{10}+\dfrac{7}{10}\right)+\left(\dfrac{4}{10}+\dfrac{6}{10}\right)+\dfrac{5}{10}\)

\(=1+1+1+1+\dfrac{5}{10}\)

\(=4+\dfrac{5}{10}\)

\(=\dfrac{45}{10}\)

\(13,25:0,5+13,25:0,25+13,25:0,125+13,25\times6\)

\(=13,25:\dfrac{1}{2}+13,25:\dfrac{1}{4}+13,25:\dfrac{1}{8}+13,25\times6\)

\(=13,25\times2+13,25\times4+13,25\times8+13,25\times6\)

\(=13,25\times\left(2+4+8+6\right)\)

\(=13,25\times20\)

\(=265\)