134260 : x = 13230 : 54

=>134260:x=245

=>x=548

sao giải có 1 câu thế cậu????

[ y + 268 ] x 268 = 4849

y + 268 = 4849 : 268

y + 268 = 4849/268

y           = 4849/268 -268

y           = -294.9067164

Đề bài sai rồi

137 x ( 13 - 3 ) = 137 x 10 = 1370

137 x 3 + 137 x 97

= 137 x (3 + 97)

= 137 x 100 = 13700

(137x99+137)-(17x101-17) = 137x(99+1)-17x(101-1) = 137x100-17x100 = 100x(137-17) = 100x120 = 12000

12000

a) 137 x 7 + 137 x 93
= 137 x ( 93 + 7 )
= 137 x 100 = 13700

b) 428 x 102 - 428 x 2
= 428 x ( 102 - 2 )
= 428 x 100
= 42800

c) 124 x 25 - 25 x 24
= 25 x ( 124 - 24 )
= 25 x 100 
= 2500

_HỌC TỐT_
 

a) 137 x 7 + 137 x 93

\(=137\times\left(7+93\right)\\ =137\times100\\ =13700\)

b) 428 x 102 - 428 x 2

\(=428\times\left(102-2\right)\\ =428\times100\\ =42800\)
c) 124 x 25 - 25 x 24

\(=25\times\left(124-24\right)=\\ 25\times100=2500\)

#Châu's ngốc

a, =12 x ( 45 + 55 )

= 12 x 100 

= 1200

b, = 25 x 4 x 280

= 100 x 280

= 28000

c, = 268 x ( 192 -92)

= 268 x 100

= 26800

Câu 2: Tính bằng cách thuận tiện nhất:

\(a)\)\(12\times45+12\times55\)

\(=\)\(12\times\left(45+55\right)\)

\(=\)\(12\times100\)

\(=\)\(1200\)

\(b)\)\(25\times280\times4\)

\(=\)\(25\times4\times280\)

\(=\)\(100\times280\)

\(=\)\(28000\)

\(c)\)\(268\times192-92\times268\)

\(=\)\(268\times\left(192-92\right)\)

\(=\)\(268\times100\)

\(=\)\(26800\)

\(152\times4+x=268+1344\\608+x=1612\\x=1612-608\\x=1004\)

152x4+

268 x 235 = 62980