Question

/ Tính hợp lí 
a ) 18 .17 -3 .6.7
b) 54-6 (17 + 9)
c) 33. (17-5) -17 .(33-5)

Answer 1

a/ 18.17-3.6.7

=18.6.3.(17-7)

=18.6.3.10

18.18.10

3240

 

Answer 2

a)=18.17-18.7

   =18.(17-7)=18.10=180

b)=54-(6.17+6.9)=54-102-54=(54-54)-102=0-102=-102

c)=(33.17-33.5)-(17.33-17.5)=33.17-33.5-17.33+17.5=(33.17-17.33)-5.(33-17)=0-80=-80