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determine the real roots of x(x-4)=0


Sagot :

The answer is x = 4 ; x = 0

SOLUTION: (solved by Completing the Square)

Distribute x through the parenthesis

→ x² - 4x = 0

To complete the square, the same value needs to be added on both sides

→ x² - 4x + ? = 0 + ?

To complete the square: x² - 4x + 4 = (x - 2)² add 4 to the expression

→ x² - 4x + 4 = 0 + 4

Factor the expression x² - 4x + 4 = 0 + 4

→ (x - 2)² = 0 + 4

→ (x - 2)² = 4

Solve the expression for x

→ √(x - 2)² = √4

→ (x - 2) = ±2

Split up into 2 possible cases

→ x - 2 = 2

x - 2 = -2

→ x = 4

x = 0

x = 4 ; x = 0