If sy + z = s(y + z), which of the following must be true?
Pick.
A) x = 0 and z = 0
B) s= 1 and y = 1
C) s = 1 and z = 0
D) s = 1 or y = 0
E) s = 1 or z = 0
sy + z = sy + sz   z = sz   case 1: z not= 0, s = z/z = 1   case 2: z = 0, 0 = s0 = 0   Combining 2 cases: s = 1 or z =0   E. is the answer.
<result>E</result>
If sy + z = s(y + z), which of the following must be true?