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2 years ago

How do i solve for x

Mathematics

1 answer:

Dafna11 [192]2 years ago

5 0

The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! so im pretty sure its 20

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If alpha and beta are the zeroes of the polynomial 6x2+x-2 find the value og alpha/beta + beta/alpha

castortr0y [4]

$6x^2+x-2=6x^2+4x-3x-2=2x(3x+2)-1(3x+2)\\\\=(3x+2)(2x-1)\\\\3x+2=0\to x=-\frac{2}{3}\\\\2x-1=0\to x=\frac{1}{2}\\\\\alpha=-\frac{2}{3};\ \beta=\frac{1}{2}\\\\\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{-\frac{2}{3}}{\frac{1}{2}}+\frac{\frac{1}{2}}{-\frac{2}{3}}=-\frac{2}{3}\cdot\frac{2}{1}-\frac{1}{2}\cdot\frac{3}{2}=-\frac{4}{3}-\frac{3}{4}\\\\=-\frac{16}{12}-\frac{9}{12}=-\frac{25}{12}=-2\frac{1}{12}$

$use\ Vieta's\ formula:\\\\\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{\alpha^2+\beta^2}{\alpha\beta}=\frac{\alpha^2+2\alpha\beta+\beta^2-2\alpha\beta}{\alpha\beta}=\frac{(\alpha+\beta)^2-2\alpha\beta}{\alpha\beta}=\frac{(\alpha+\beta)^2}{\alpha\beta}-2\\\\\alpha+\beta=\frac{-b}{a};\ \alpha\beta=\frac{c}{a}\\\\\frac{(\alpha+\beta)^2}{\alpha\beta}-2=\frac{\left(\frac{-b}{a}\right)^2}{\frac{c}{a}}-2=\frac{b^2}{a^2}\cdot\frac{a}{c}-2=\frac{b^2}{ac}-2$

$6x^2+x-2\\\\a=6;\ b=1;\ c=-2\\\\\frac{\alpha}{\beta}+\frac{\beta}{\alpha}=\frac{1^2}{6\cdot(-2)}-2=\frac{1}{-12}-2=-2\frac{1}{12}$

7 0

2 years ago

A coordinate grid showing Number of Classes on the horizontal x-axis and Total Cost in dollars on the vertical y-axis with 2 lin

Oksana_A [137]

The system of equations representing these costs are; y = 7.5x and y = 5.5x + 10

<h3>How to find the equation of a line?</h3>

The slope of the first line is;

m = (y2 - y1)/(x2 - x1)

m = (32 - 10)/(4 - 0)

m = 5.5

Now, the first coordinate has a y-intercept of 10. Thus, the equation here for the cost is; y = mx + c = 5.5x + 10

The slope of the second line is;

m = (y2 - y1)/(x2 - x1)

m = (15 - 0)/(2 - 0)

m = 7.5

Now, the first coordinate has a y-intercept of 0. Thus, the equation here for the cost is; y = mx + c = 7.5x + 0 = 7.5x

Thus, the system of equations representing these costs are;

y = 7.5x and y = 5.5x + 10

Read more about Equation of a line at; brainly.com/question/13763238

#SPJ1

5 0

1 year ago

Find the midpoint of a segment whose endpoints are (9, –7) and (–3, 5).

suter [353]

For this question, you would have to use the midpoint formula.
(X1 +X2 / 2 , Y1 + Y2 / 2)

In other words,
(9 + -3 / 2 , -7 +5 / 2)
(6 / 2 , -2 / 2)
(3 , -1)

Your midpoint is (3, -1)

7 0

2 years ago

The perimeter of a rectangle is 68 ft. Find the dimensions of the rectangle if the ratio of the length to the width is 9 : 8. Wh

Kipish [7]

I think the best answer is d since 18x + 16x

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2 years ago

How many sides does a circle have

Irina-Kira [14]

A circle doesnt have a sides so 0

4 0

2 years ago

Read 2 more answers