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What are the solutions of x² - 5x+7=0?

What are the solutions of x² - 5x+7=0?-example-1
User Ruthi
by
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1 Answer

3 votes

Answer:

x = 5/2 + (i sqrt(3))/2 or x = 5/2 - (i sqrt(3))/2

Explanation:

Solve for x:

x^2 - 5 x + 7 = 0

Subtract 7 from both sides:

x^2 - 5 x = -7

Add 25/4 to both sides:

x^2 - 5 x + 25/4 = -3/4

Write the left hand side as a square:

(x - 5/2)^2 = -3/4

Take the square root of both sides:

x - 5/2 = (i sqrt(3))/2 or x - 5/2 = -(i sqrt(3))/2

Add 5/2 to both sides:

x = 5/2 + (i sqrt(3))/2 or x - 5/2 = -(i sqrt(3))/2

Add 5/2 to both sides:

Answer: x = 5/2 + (i sqrt(3))/2 or x = 5/2 - (i sqrt(3))/2

User WhiteMist
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