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liubo4ka [24]
3 years ago
8

Solve x2 - 4x - 7 = 0 by completing the square. What are the solutions?

Mathematics
1 answer:
Roman55 [17]3 years ago
5 0

Answer:

x= 2 + √11 or x = 2 −√11

Step-by-step explanation:

I am going to complete the square step-by-step.

x² − 4x − 7=0

Step 1: Add 7 to both sides.

x² − 4x − 7+ 7 = 0 + 7

x² − 4x = 7

Step 2: The coefficient of -4x is -4. Let b = -4.

Then we need to add (b/2)² = 4 to both sides to complete the square.

Add 4 to both sides.

x² − 4x + 4 = 7 + 4

x² − 4x + 4 = 11

Step 3: Factor left side.

(x−2)² = 11

Step 4: Take square root.

x − 2 = ±√11

Step 5: Add 2 to both sides.

x − 2 + 2 = 2 ±√11

x = 2 ±√11

x= 2 + √11 or x = 2 −√11

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3 0
3 years ago
Please help, see attachment for equation!
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Answer:

The answer to your question is the last option

Step-by-step explanation:

Quadratic equation

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Order the equation from the highest power to the lowest power. Do not consider 2 because it is not consider in the options given.

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