简答题
GRE
2012-10-13
If 2y-X=1 and y-X=2,then which of the following is true?
参考答案
暂无
答案解析
D.Because Y—χ=2.you know that Y=2+χ.You can substitute this into 2y—χ=1 to make it 2(2+χ)-χ=1,which simplifies t0 4+χ=1 0rχ=-3.You then substitute y=2+χ=2+(-3)=-1 and conclude that χ=-3 and Y=-1.