Question

判断下列等式变形是否正确,并说明理由.

Answer 1

1. 0.75y=5-0.25y ---->移项得:0.75y+0.25y=5--->y=5 所以是正确的

2. 10/50 x-14=5/20 x+3 ---->整理得:1/5 x-14=1/4 x+3 ----->移项得:1/5 x-1/4 x=3+14---->整理得:4/20x-5/20 x=17---->-1/20 x=17----->两边各自乘于 -20得:x= - 340