Question

Solve: 4x^-2 – 3x^-1– 1 = 0

Answer 1

1, -4

Explanation:

• 4x^-2 – 3x^-1– 1 = 0

Let x^-1 = 1/x = y

• 4y^2 - 3y - 1 = 0
• 4y^2 - 4y + y - 1 = 0
• (y - 1) (4y + 1) = 0

1. Root 1

• y - 1 = 0
• y = 1
• 1/x= 1
• x = 1

2. Root 2

• 4y + 1 = 0
• 4y = -1
• y = -1/4
• 1/x = - 1/4
• x = -4