x-2y+Z=01-2*0+z=0z=-1直线方程式:x-2y-1=0
直线x–2y–2=0y= (1/2)x + 1/2过点（1，0）且与直线x–2y–2=0平行的直线方程是y-0 = (1/2)(x-1)y= (1/2)(x-1)
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