8/25/2014 If a(x + 2) + b(x – 1) = 3 for all x, then a =

a) -1
b) 0
c) 1
d) 2
e) 3

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8/25/2014 Solution. C. Since the equation is true for all x, and we seek a, we can cleverly substitute x = 1 throughout so that the expression with b collapses → a = 1.