Answer:
x = 2 or x = 1 or x = -1 or x = 3/2 thus from the answers given only A: applies
Explanation:
Solve for x over the real numbers:
2 x^4 - 7 x^3 + 4 x^2 + 7 x - 6 = 0
The left hand side factors into a product with four terms:
(x - 2) (x - 1) (x + 1) (2 x - 3) = 0
Split into four equations:
x - 2 = 0 or x - 1 = 0 or x + 1 = 0 or 2 x - 3 = 0
Add 2 to both sides:
x = 2 or x - 1 = 0 or x + 1 = 0 or 2 x - 3 = 0
Add 1 to both sides:
x = 2 or x = 1 or x + 1 = 0 or 2 x - 3 = 0
Subtract 1 from both sides:
x = 2 or x = 1 or x = -1 or 2 x - 3 = 0
Add 3 to both sides:
x = 2 or x = 1 or x = -1 or 2 x = 3
Divide both sides by 2:
Answer: x = 2 or x = 1 or x = -1 or x = 3/2