Answer:
The zeroes are -6, 1/2 and 2.
Step-by-step explanation:
f(x) = 2x3 + 7x2 - 28x + 12 = 0
From the first and last coefficient 2 and 12, one guess for a zero is x = 2.
So substituting x = 2:
f(2) = 16+ 28 - 56 + 12 = 0
So x = 2 is a zero and x - 2 is a factor of f(x)
Performing long division:
x - 2)2x3 + 7x2 - 28x + 12( 2x2 + 11x - 6 <------- Quotient
2x3 - 4x2
11x2 - 28x
11x2 - 22x
- 6x + 12
-6x + 12
.............
Now we solve
2x2 + 11x - 6 = 0
(2x - 1)(x + 6) = 0
2x - 1 = 0 or x + 6 = 0, so:
x = 1/2, x = -6.
