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I really don't understand how to complete the square in maths. Please help!

I really don't understand how to complete the square in maths. Please help!-example-1

2 Answers

2 votes

Answer:

the perfect squares are,

1. (x + 4)² - 10

2. (x + 6)² - 37

Explanation:

1.

x² + 8x + 6 = 0

the steps to make a perfect square are as follows:

1. move the constant to the right side of the equation,

x² + 8x = -6

2. take the half of the x term which in the given equation is 8,

8/2 = 4

3. square the half of the x term, 4² = 16

4. add the square to both sides of the equation,

x² + 8x + 16 = -6 + 16

the given equation is a perfect square now,

(x + 4)² = 10

(x + 4)² - 10

as we know that, (a + b)² = a² + b² + 2ab

(x + 4)² = x² + 16 + 8x which proves that our perfect square is right.

2.

x² + 12x - 1 = 0

let's follow the same steps again,

1. move the constant to the right side of the equation,

x² + 12x = 1

2. let's take half of x term which is 12,

12/2 = 6

3. let's square the half of the x term, 6² = 36

4. let's add the square of the half of the x term to both sides of equation,

x² + 12x + 36 = 1 + 36

the equation is a perfect square now,

(x + 6)² = 37

(x + 6)² - 37

as we know that, (x + 6)² = x² + 36 + 12x which verifies that our perfect square is right

answered
User Greg Reda
by
7.8k points
3 votes

Answer:

(x + 4)² - 10 , (x + 6)² - 37

Explanation:

to complete the square

add/ subtract ( half the coefficient of the x- term)² to the first 2 terms

(1)

x² + 8x + 6

= x² + 2(4)x + 16 - 16 + 6

= (x + 4)² - 16 + 6

= (x + 4)² - 10

(2)

x² + 12x - 1

= x² + 2(6)x + 36 - 36 - 1

= (x + 6)² - 36 - 1

= (x + 6)² - 37

answered
User Greggreg
by
8.0k points

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