What is the of A in a partial fraction decomposition below?

8x+28 / (x-1) (x+2) (x+3) = A/x-1 + B/x+2 + C/x+3

3

Step-by-step explanation:

(8x + 28) / ((x - 1) (x + 2) (x + 3)) = A / (x - 1) + B / (x + 2) + C / (x + 3)

Multiply both sides by (x - 1) (x + 2) (x + 3).

8x + 28 = A (x + 2) (x + 3) + B (x - 1) (x + 3) + C (x - 1) (x + 2)

If x = 1:

8 + 28 = A (3) (4)

36 = 12A

A = 3