Question

$( \frac{7}{8} - \frac{5}{6} ) + ( \frac{8}{9} - \frac{7}{9} )$
o resultado da expressao é 11/72​

Answer 1

Oi !

( 7 / 8 - 5 / 6 ) + ( 8 / 9 - 7 / 9 )

= 7 • 3 / 8 • 3 - 5 • 4 / 6 • 4 + 8 / 9 - 7 / 9

= 7 • 3 / 24 - 5 • 4 / 24 + 8 / 9 - 7 / 9

= 7 • 3 - 5 • 4 / 24 + 8 / 9 - 7 / 9

= 1 / 24 + 1 / 9

mmc ( 24 , 9 ) = 72

= 3 + 8 / 72

= 11 / 72