①|a-3|+|4b-8|+|c+5|=0求2a-4b+2c的值
a=3 b=2 c=-5
2a-4b+2c=6-8-10=-12
②若a是-3的相反数,且4a-2x=6求x的值
a=3
12-2x=6
2x=6
x=3
③|x|=2,|y|=10且x＜y,求x+y的值
x=±2 y=10
x+y=12或8
④|1-2|+|-3|+|3-4|+.+|99-100的值|
=1*50+3
=53
⑤|1-1/2|+|1/2-1/3|+1/3-1/4|+.+|1/999-1/1000|的值
=1-1/2+1/2-1/3+1/3-1/4+.+1/999-1/1000
=1-1/1000
=999/1000
⑥求|1/3-1/2|+|1/2-1|的值|
=1/2-1/3+1-1/2
=2/3
⑦求|1/10-1/9|+|1/9-1/8|+|+...+|1/3-1/2|的值
=1/2-1/3+1/3-1/4+.+1/8-1/9+1/9-1/10
=1/2-1/10
=4/10
=2/5