幫我解答以下算式

1)
a) 0-[12+(-3)]=0-(12-3)
=0-9
= -9
b) (-12)除(1/3)x(1/-4)=(-12)x3 除 -4
=3*3
= 9

2) x=2, y=3 , z=5
4x-2y
=4(2)-2(3)
=8-6
= 2

1.)
(a)0-[12+(-3)]=-9
(b)(-12)除(+3分之1)x(-4分之1)=9