Question

Calcule as expressões :

a - ( 1/2 - 1/5 ) - ( 7/4 - 5/4 )

b- ( 3/4 + 4/3 ) x ( 8/7 - 7/8)

c - 1/2 x 3/5 - 1/3 x 2/5 + 3/2 x 7/3 =

Answer 1

   
A) mmc (2,5) = 10
              (5*1-2*1) - (2/4)
              5-2-(2/4)
              4*5-4*2-2
              20-8-2
              10

B) mmc (4,3) = 12 e (7,8) = 56
             (3*3+4*4)*(8*7-7*8)
             (9+16)*(56-56)
             25*0
             0

C) mmc (2,5) = 10, (3,5) = 15 e (2,3) = 6
              ((5*1) * (2*3))-((5*1)*(3*2))+((3*3)*(2*7))=
              (5*6)-(5*6)+(9*14)=
               30-30+126
                0+126 = 126