Find the value(s) of a and b so that the system has 2x-y-2az+t -2x+ay-3: 2x y + (2a+1) + (a+1)t -- (a) no solution? = b 4 = 0 -26-2 -2x+y+ (12a): - 2t - (b) exactly one solution? Find this solution. (c) infinitely many solutions? Find these solutions.