Question

calcule 1-[5+(1-9)]=

Answer 1

$1- [5+(1-9)] =1-[5-8] = 1- [-3] = 1 +3 = 4$

Answer 2

1 - [5 + (1 - 9)] =

1 - [5 + (-8)] =

1 - [5 - 8] =

1 - [-3] =

1 + 3 = 4