問一些maths??急.................help*

1a). 3x/2 = -3x/4
1/2 = -1/4 ???
Error!

1e). 1/3 (1-2x) + 1/6 (4-5x) + 1/42
= (1-2x) / 3 + (4-5x)/6 + 1/42
= [14 (1-2x) + 7 (4-5x) + 1] / 42
= (14 - 28x + 28 - 35x + 1) / 42
= (-63x + 43) / 42
= - (63x - 43) / 42

1a的答案就是0如果唔係就係無答案件!!
1e這個不是未知數吧??為什麼沒有什麼=什麼的答案?