94.2k views
3 votes
2x²-12x+8 = 0

solve for x ​

User Libert
by
6.8k points

1 Answer

3 votes

Answer:

x = 3 + sqrt(5) or x = 3 - sqrt(5)

Explanation:

Solve for x over the real numbers:

2 x^2 - 12 x + 8 = 0

Divide both sides by 2:

x^2 - 6 x + 4 = 0

Subtract 4 from both sides:

x^2 - 6 x = -4

Add 9 to both sides:

x^2 - 6 x + 9 = 5

Write the left hand side as a square:

(x - 3)^2 = 5

Take the square root of both sides:

x - 3 = sqrt(5) or x - 3 = -sqrt(5)

Add 3 to both sides:

x = 3 + sqrt(5) or x - 3 = -sqrt(5)

Add 3 to both sides:

Answer: x = 3 + sqrt(5) or x = 3 - sqrt(5)