Whats (346 +873 x 6) 7

Sviatoslav solved the quadratic equation x^2-x-1=0 by completing the square. In the process, he came up with the equivalent equa

zimovet [89]

Answer:

$x=\frac{1+\sqrt5}{2}$ and $x=\frac{1-\sqrt5}{2}$

and b= $\frac{5}{4}$

Step-by-step explanation:

We are given that a quadratic equation

$x^2-x-1=0$

We have to solve the equation by completing square and find the value of b.

$(x)^2-2\times x\times \frac{1}{2}+(\frac{1}{2})^2-(\frac{1}{2})^2-1=0$

$(x-\frac{1}{2})^2-\frac{1}{4}-1=0$

$(x-\frac{1}{2})^2-\frac{1-4}{4}=0$

$(x-\frac{1}{2})-\frac{5}{4}=0$

$(x-\frac{1}{2})^2-(\frac{\sqrt5}{2})^2=0$

$(x-\frac{1}{2})^2=(\frac{\sqrt5}{2})^2$

$x-\frac{1}{2}=\frac{\sqrt5}{2}$ and $x-\frac{1}{2}=-\frac{\sqrt5}{2}$

$x=\frac{\sqrt5}{2}+\frac{1}{2}=\frac{1+\sqrt5}{2}$

And $x=\frac{1}{2}-\frac{\sqrt5}{2}=\frac{1-\sqrt5}{2}$

Therefore, $x=\frac{1+\sqrt5}{2}$ and $x=\frac{1-\sqrt5}{2}$

and b= $\frac{5}{4}$

6 0

3 years ago

12×2+7x=<br>I need help understanding why the x is there

posledela

12*2+7(x) you need to solve for x

8 0

3 years ago

Mir evaluated 5x - (x + 3)2 for x = 2, as shown. Describe Amir's mistake and find the correct answer. 5(2) - (2 + 3)2 = 10 + (-5

sleet_krkn [62]

Answer:correct answer =0

Step-by-step explanation:

Step 1

5x - (x + 3)2

Putting the coefficient of x =2 in the equaton we have

5(2) - (2 + 3)2

Solving out

5(2) - (5)2

= 10- 10

=0

Step 2

Amir's mistake was in the multiplication and wrong use of the negative sign of the bolded below

5(2) - (2 + 3)2 = 10 + (-5)2 = 10 + 25 = 35

-(5)2 cannot give 25 instead 10, so him getting a 25 and wrong use of the negative and positive made his answer wrong.

The right answer as calculated in step 1 = 0

4 0

3 years ago

Read 2 more answers

What's 2+2 if you add 4 and subtract 1

MariettaO [177]

It would be 7 because 2+2=4+4=8-1=7. Hope this helped.

8 0

3 years ago

Read 2 more answers

Drag the tiles to the boxes to form correct pairs.

Oxana [17]

When two lines intersect at 90° degrees angle, the lines are perpendicular to each other. Two perpendicular lines, their slope will give a product of -1

i.e. if the first's line slope is 5, then the second line's will be -1 ÷ 5 = -¹/₅

To find the slope of a line, we divide the vertical distance by the horizontal distance.

We'll use the trial and error method to find the right pairing

Let's start with A(3, 3) and B(12, 6)

Vertical distance =

Horizontal distance =

The slope AB = ³/₉ = ¹/₃

We want BC to have a slope -1 ÷ ¹/₃ = -3

Try C(16, -6); check the slope with B(12, 6)

Vertical distance =

Horizontal distance =

Slope of BC = -12 ÷ 4 = -3

The slope BC = -3 is the value we want so, tile 1 pair with tile 4

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Let's do A(-10, 5) and B(12, 16)

Vertical distance = 16 - 5 = 11

Horizontal distance = 12 - -10 = 22

Slope AB = ¹¹/₂₂ = ¹/₂

The perpendicular slope would be -1 ÷ ¹/₂ = -2

Try C(18, 4) with B(12, 16)

Vertical distance = 16 - 4 = 12

Horizontal distance = 12 - 18 = -6

Slope BC = ¹²/₋₆ = -2

Slope BC and slope AB perpendicular, so tile 3 matches with tile 6

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Let's try A(12, -14) and B(-16, 21)

Vertical distance = 21 - -14 = 35

Horizontal distance = -16 - 12 = -28

The slope AB = ³⁵/-₂₈ = ⁵/₋₄

We need the perpendicular slope to be -1 ÷ -⁵/₄ = ⁴/₅

Try C(-11, 25)

Vertical distance with B = 25 - 21 = 4

Horizontal distance with B = -11 - -16 = 5

The slope = ⁴/₅

Tile 7 matches tile 8

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Take A(-12, -19) and B(20, 45)

Vertical distance = 45 - -19 = 64

Horizontal distance = 20 - -12 = 32

Slope AB = ⁶⁴/₃₂ = 2

We need the perpendicular slope to be -1 ÷ 2 = -¹/₂

We have C(6, 52) and checking the slope with B(20, 45)

Vertical distance = 45 - 52 = -7

Horizontal distance = 20 - 6 = 14

The slope is ⁻⁷/₁₄ = -¹/₂

Tile 9 pairs with tile 2

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Conclusion

Tile 1 ⇒ Tile 4

Tile 3 ⇒ Tile 6

Tile 7 ⇒ Tile 8

Tile 9 ⇒ Tile 2

Tile 5 and Tile 10 do not have pairs

5 0

3 years ago