Question

calcule o valor da expressão numérica

(-7/9):(-7/9)-(-5/6)²=

(-10).(-2/5)²-(-2/3):(+8/9)=

Answer 1

a) (-7/9) : ( -7/9) - ( -5/6)² =
= ( - 7/9) . (-9/7) - ( + 25/36) =
= +1 - 25/36 =
= 36/36 - 25/36=
= 6/36 =
= 1/6

b) (-10).(-2/5)² - (-2/3) : ( +8/9) =
=  (-10) .4/25  - (-2/3) . (9/8) =
= (-2). 4/5  - ( - 3/4)=
= - 8/5  + 3/4=
= -32 / 20 + 15/ 20=
= - 17/ 20