Question

17+{[26-(15-8)+(8-4)]-9}

Answer 1

17+{[26-(15-8)+(8-4)]-9}
17+{[26-7+4]-9}
17+{[26-3]-9}
17+{23-9}
17+14=31

Answer 2

17+{[26-(15-8)+(8-4)]-9}=

17+{[26-7+4]-9}

17+{[26-11]-9}

17+{15-9}

17+6

=23

espero ter ajudado!