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3 years ago

Use the quadratic formula to solve the equation. x2 + 7x – 4= 0

Mathematics

1 answer:

larisa [96]3 years ago

8 0

Answer:

Well.

\ /

 2 solutions 

x =(-7-√65)/2=-7.531

 x =(-7+√65)/2= 0.531

/ \

Using the quadratic formula..

2.3 Solving x2+7x-4 = 0 by the Quadratic Formula .

According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :

- B ± √ B2-4AC

x = ————————

In our case, A = 1

B = 7

C = -4

Accordingly, B2 - 4AC =

49 - (-16) =

Applying the quadratic formula :

-7 ± √ 65

x = —————

√ 65 , rounded to 4 decimal digits, is 8.0623

So now we are looking at:

x = ( -7 ± 8.062 ) / 2

\ /

Two real solutions:

x =(-7+√65)/2= 0.531

or:

x =(-7-√65)/2=-7.531

\ /

*eliza*

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VladimirAG [237]

Answer:

$y=2x^2-4x-8$

Step-by-step explanation:

Factored form of a parabola

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where:

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a is some constant.

Given x-intercepts:

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Therefore:

$\implies y=a(x-(1+\sqrt{5}))(x-(1-\sqrt{5}))$

$\implies y=a(x-1-\sqrt{5})(x-1+\sqrt{5})$

To find a, substitute the given point (4, 8) into the equation and solve for a:

$\implies a(4-1-\sqrt{5})(4-1+\sqrt{5})=8$

$\implies a(3-\sqrt{5})(3+\sqrt{5})=8$

$\implies4a=8$

$\implies a=2$

Therefore, the equation of the parabola in factored form is:

$\implies y=2(x-1-\sqrt{5})(x-1+\sqrt{5})$

Expand so that the equation is in standard form:

$\implies y=2(x^2-x+\sqrt{5}x-x+1-\sqrt{5}-\sqrt{5}x+\sqrt{5}-5)$

$\implies y=2(x^2-x-x+\sqrt{5}x-\sqrt{5}x+\sqrt{5}-\sqrt{5}+1-5)$

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$\implies y=2x^2-4x-8$

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2 years ago

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umka2103 [35]

Answer:

$\frac{y}{x^2}+\frac{y}{x^3}=\frac{yx+y}{x^3}$

Step-by-step explanation:

Given the expression

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Let us perform the operation and express your answer as a single fraction

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$=\:\frac{x^2\left(xy+y\right)}{x^5}$

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Therefore, we conclude that:

$\frac{y}{x^2}+\frac{y}{x^3}=\frac{yx+y}{x^3}$

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Answer:

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