Question

[bùi thị thanh hồng]

a ) b :(119 x a +2005)+199:a -b x 2005

           với a = 119 ; b = 0

b) 100 : { 2 x [ 52 - (25 - 8 )]}

c)  12 : { 390 : [ 500 - ( 125 + 25 :7 )]}

Answer 1

[gunjupyo]

a) thay a = 119 ;b = 0 vào bt : ( 119 x a +2005 ) +119 :a- b x 2005 ta có : 

( 119 x 199+2005) +119 :119 -0 x2005

<=> (14161+2005 ) +119 : 119 -0 x 2005

<=>16166+119 : 199 -0 x 2005

<=> 16166+1 - 0 x 2005 

<=> 16166 +1 - 0 

<=> 16167

b) 100 : {2 x [ 52-(25 - 8 )]}

<=> 100 : { 2 x [ 52 - 17] }

<=> 100 : { 2 x 35 }

<=> 100 : 70 

<=> \(\frac{10}{7}\)

c) 12 : { 390 : [ 500 - ( 125 +25 : 7 ) ] }

<=> 12 : { 390 : [ 500 - ( \(\frac{900}{7}\) ) ] }

<=> 12 : { 390 : [ \(\frac{2600}{7}\) ] }

<=> 12 : { \(\frac{21}{20}\) }

<=> \(\frac{80}{7}\)