-1/2+2 1/3 x (-4 1/2) - 1/2=

-1/2+2 1/3×(-4 1/2)-1/2
7/3×(-9/2)-1
-63/6-1=-70/6=-11 2/3

-1/2 + 2 1/3 x ( - 4 1/2 ) - 1/2

= -1/2 +( 7/3 x -9/2 ) - 1/2
= - 1/2 + ( -63/6 ) - 1/2
= -1/2 - 63/6 - 1/2
= -3/6 - 63/6 - 3/6
= -69/6
= -23/2