báo cáo

a/ 93

b/ 124-(5²⁴-4)

a/93

b/124-(5²⁴-4)

tick mk nha , mk tick lại

989x69-687x69-292x69

=69x(989-687-292)

=69x10

=690

989×69-687×69-292×69

= ( 989 - 687 - 292 ) x 69

= 10 x 69

= 690

90 + 89 + 11

= 90 + ( 89 + 11 )

= 90 + 100

= 190

687+ 3

= 690

1 ) 190

 2) 690

A = ( 1374 x 57 + 687 x 86 ) : ( 26 x 13 + 74 x 14 )

A = 137,67 : 762

A = 4589/25400

A = 344 x 687 - 343

A = (343 + 1) x 687 - 343

A = 343 x 687 + 687 - 343

A = 343 x 687 + (687 - 343)

A = 343 x 687 + 345 = B

Vậy A = B

( 137 x 57 + 687 x 86 ) : ( 26 x 13 + 74 x 16 )

= ( 7809 + 59082 ) : ( 338 + 1184 ) 

= 66891 : 1522

= 43.94940867279895

bằng 100 cơ bạn

32560:35=930(dư 2)

67034:356=188(dư 53)

90143:541=166,623

687x315=216405

32560:35=930(dư 2)

67034:356=188(dư 53)

90143:541=166,623

687x315=216405

Tính nhanh :

a , ( 1374 : 57 + 687 : 86 ) : ( 26 x 13 + 74 x 14 )

b , ( 124 x 237 + 152 ) : ( 870 + 235 x 122 )

a, ( 1374 : 57 + 687 : 86 ) : ( 26 x 13 + 74 x 14 )

= (1374 x 57 + 1374 x 43) : (26 x 13 + 74 x 13 + 74)

= (1374 x 100) : (13 x 100 + 74) 

= 137400 : 1374

= 100 .

b, ( 124 x 237 + 152 ) : ( 870 + 235 x 122 )

= ( 124 x 235 + 248 + 152 ) : ( 235 x 124 + 400 )

= ( 124 x 235 + 400 ) : ( 235 x 124 + 400 )

= 1 .