a ) 17 x 4 = ( 15 + 2 ) x 4 = 15 x 4 + 2 x 4 = 60 + 8 = 68

      25 x 28 = 25 x ( 20 + 8 ) = 25 x 20 + 25 x 8 = 500 + 200 = 700

b ) 13 x 12 = 13 x ( 10 + 2 ) = 13 x 10 + 13 x 2 = 130 + 26 = 156

      53 x 11 = 53 x ( 10 + 1 ) = 53 x 10 + 53 x 1 = 530 + 53 = 583

      39 x 101 = 39 x ( 100 + 1 ) = 39 x 100 + 39 x 1 = 3900 + 39 = 3939

a) Ta có:

\(17\times4=\left(15+2\right)\times4=15\times4+2\times4=60+8=68\)

\(25\times28=25\times\left(20+8\right)=25\times20+25\times8=500+200=700\)

b) Ta có:

\(13\times12=13\times\left(10+2\right)=13\times10+13\times2=130+26=156\)

\(53\times11=53\times\left(10+1\right)=53\times10+53\times1=530+53=583\)

\(39\times101=39\times\left(100+1\right)=39\times100+39\times1=3900+39=3939\)

giải i mn huhu pls

cần dc giải mai tui họccc

a,134

b,91

c,59

d,30

e,107

g,50

h,9

y,110

a, = 134

b, 91

c, 59

d, 30

e, 107

g, 50

h 9

p, 110

a) 27x6 = 3*9*6 = 162

b) 99x4 = 11x9x4 = 396

c) 125x16 = 5x5x5x4x4=2000

2 x 31 x 12+ 4 x 6 x 42 + 8 x 3 x 27 = 24 x 31 + 24 x 42 + 24 x 27 = 24 x (27 + 31 + 42) = 24 x 100 = 2400

b) 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41 = 36 x (28 + 82)  + 64 x (69 + 41) = 36 x 110 + 64 x 110 = 110 x (64 + 36) = 110 x 100 = 11000

a. 4.37.25.50.12

  =(4.25).(50.12).37

  =100.600.37

  =2220000

\(a.\left(4.50\right).\left(25.12\right).37\)

\(=200.300.37=2220000\)

\(b.\left(46+54\right)+\left(17+83\right)\)

\(=100+100=200\)

\(c.87.\left(36+69\right)=87.105=9135\)

\(d.\left(135+65\right)+\left(360+40\right)\)

\(=200+400=600\)

\(e.\left(463+137\right)+\left(318+22\right)\)

\(=600+340=940\)

\(60+x-34=43\Rightarrow x=43+34-60=17\)

\(23x-6.23+69x=230\)

\(\Rightarrow23x+69x=230+6.23\)

\(\Rightarrow92x=368\Rightarrow x=368:92\Rightarrow x=4\)

\(\left(15.24-x\right):0,25=100:0,25\)

\(\Rightarrow\left(360-x\right)=100:0,25.0,25\)

\(\Rightarrow360-x=100\Rightarrow x=360-100=260\)

\(\left(7x+8\right):5=10\Rightarrow\left(7x+8\right)=10.5\)

\(\Rightarrow7x+8=50\Rightarrow7x=50-8\Rightarrow7x=42\Rightarrow x=42:7=6\)

\(280:\left(7+3x\right)=4\Rightarrow\left(7+3x\right)=280:4\)

\(\Rightarrow7+3x=70\Rightarrow3x=70-7\Rightarrow3x=63\Rightarrow x=63:3=21\)

\(\left(x+5\right)x19:13=57\)

\(\Rightarrow\left(x+5\right)x19=57.13\)

\(\Rightarrow\left(x+5\right)=741:19\Rightarrow x+5=39\Rightarrow x=39-5=34\)

\(4\left(36-4x\right)=64\)

\(\Rightarrow\left(36-4x\right)=64:4\)

\(\Rightarrow36-4x=16\)

\(\Rightarrow4x=36-16\Rightarrow4x=20\Rightarrow x=20:4=5\)

\(\left(7,6:1,9\right)x=3,2\)

\(\Rightarrow4x=3,2\Rightarrow x=3,2:4=0,8\)

\(\left(x:2+50\right):5=12\)

\(\Rightarrow x:2+50=12.5\)

\(\Rightarrow x:2=60-50\Rightarrow x:2=10\Rightarrow x=10.2=20\)

cứu tui

1.53x201=10653

2.

a)4 xX-15x4=6x15+X

<=>4x-60=90+x

<=>4x-x=60+90

<=>3x=150

<=>x=50

b(102+28-2x):20-5=1

<=>(130-2x):20=6

<=>130-2x=120

<=>2x=10

<=>x=5

c)1999x-x=1999+1997+1999

<=>1998x=5995

<=>\(x\approx3\)

d)105-5x=150:15

<=>105-5x=10

<=>5x=95

<=>x=19

e)(x+1)+(x+2)+(x+3)+...+(x+6)=78

<=>6x+21=78

<=>6x=57

<=>x=9,5

1) 53x201=53x200+53=10600+53=10653

2a)

4x-15x4=6x15+x

4x-60=90+x

4x-x=90+60

3x=150

x=50

b) x=5

c) x=3

d)x=19

e) x=9,5

6B, 7A, 8D