a: Sửa đề: \(17\cdot58\cdot43+57\cdot17\cdot28\)

\(=17\times\left(58\times43+57\times28\right)\)

=17x4090

=69530

b: Sửa đề: \(43\times53-2,6\times\left(630-315\times2\right)\)

=43x53-2,6x(630-630)

=43x53

=2279

c: \(\frac{45\times16-17}{45\times15+28}\)

\(=\frac{45\times15+45-17}{45\times15+28}\)

\(=\frac{45\times15+28}{45\times15+28}\)

=1

d: 104x68-36x52

=52x2x68-36x52

=52x136-36x52

=52x(136-36)

=52x100

=5200

104.68-36.52

=104.68-18.2.52

=104.68-18.104

=(68-18)104

=50.2.52

=100.52=5200

104.68-36.52

=52.2.68-36.52

=52.136-36.52

=52.(136-36)

=52.100

=5200

Làm mẫu 1 câu nhé

a) 

<=> 3 - 17 + x = 579 - 36 - 579

<=> -14 + x     = - 36

<=>          x     = -36 + 14

<=>          x     = -22

Các câu sau tương tự nà :)

giải nốt đi

a) x = 160

b) x = 5

c) x = 107

d) x = 3

a) 125.3+125.125.6

=125.3+125.750

=125.(3+750)

=125.753

=94125

b) (245.99+245)-(145.101-145)

=(245.(99+1))-(145.(101-1))

=245.100-145.100

=(245-145).100

=100.100

=10000

c) 154.(28+52)-45.(26+54)

=154.80-45.80

=(154-45).80

=109.80

=8720

a) 125x3+125+125x6

=125x(3+1+6)

=125x10

=1250

b) (245x99+245)-(145x101-145)

=(245x99+245)-(145x100)

=(245x100)-14500

=24500-14500

10000

c) 154x80-45x80

=80x(145-45)

=80x100

=8000

a) ( 36 x 28 + 36 x 45 ) : 73

= 36 x (28 + 45 ):73

=36 x 73 :73

= 36 x (73 : 73)

= 36 x 1

= 36

b) ( 98 x 17 - 26 x 17 ) : 72

= 17 x (98-17):72

= 17 x 72 :72

=17 x (72 :72)

= 17 x 1

= 17

a) ( 36 x 28 + 36 x 45 ) : 73 = 36 

b) ( 98 x 17 - 26 x 17 ) : 72 = 17 

a ) x − 28   :   − 12   =   − 5 x − 28 =   − 5 .   − 12 x − 28     =  6 0   x   =  6 0   + 28 x   =  88

b ) x + 15   :   − 28   =  8 x + 15  = 8 . − 28 x + 15  = −  224   x   =   − 224  –  15 x   =   − 239

c ) x + 3 0   :   − 45   =   −  4 x + 3 0   =   − 4 .   − 45 x + 3 0   =  18 0 x   = 18 0   –  3 0 x   = 15 0