Answer:
-1, 2, 0.5, 0.5
Explanation:

Using synthetic division for x=-1 we find that
-1 4 -8 -3 7 -2
-4 12 -9 2
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4 -12 9 -2 0
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Thus quotient is

Again try synthetic division by x-2
2 4 -12 9 -2
8 -8 2
-----------------------------------
4 -4 1 0
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Thus quotient is

Hence zeroes of the polynomial f(x) are
-1, 2, 0.5, 0.5