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4 years ago

How do you work out this problem using completing the square x2 - 4x - 80 = 0

Mathematics

2 answers:

Ugo [173]4 years ago

7 0

x^2 - 4x = 80

x^2 - 4x + 4 = 80 + 4 (Divide b, which is 4, by 2 and square it.)

x^2 - 4x + 4 = 84

sqrt(x + 2)^2 = sqrt(84)

x + 2 = plus or minus sqrt(84)

Subtract 2 from both sides

x = -2 plus or minus sqrt(84)

yulyashka [42]4 years ago

3 0

Answer:

A value that satisfies this equation is called a root, zero or solution of the equation!! We have three ... Solve each by factoring. 1) x2 + 4x -5 = 0 ... Follow the explanation and sample problem to review completing the square.

Step-by-step explanation:

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