Find all scalars C, if any exist, such that given statement is true. i+ cj +(c-1)k i is in the span of i+2j + k and 3i +6j + 3k Thank you! Solution i+ cj +(c-1)k = a(i+2j + k) + b( 3i +6j + 3k) --> a + 3b = 1 (1) 2a + 6b = c (2) a + 3b = c - 1 (3) From (1) and (2): 2(a + 3b) = 2(1) --> 2a + 6b = 2 = c Therefore c = 2. You can also check that for c = 2, the third equation and the first equation are the same, So this values satisfies the third equation too..