|x+2|=0
x=-2
|y+5|-4的值为负4
|y+5|-4=-4
|y+5|=0
y=-5
数轴上z对应的点与-1的距离为6
z=-7 或z=51-1/2-1/4-1/8-1/16-1/32-1/64-1/128-1/256