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3 years ago

Y square - y - 20 (factorisation)

Mathematics

1 answer:

Vera_Pavlovna [14]3 years ago

3 0

Answer:

(y - 5)(y + 4)

Step-by-step explanation:

Given

y² - y - 20

Consider the factors of the constant term (- 20) which sum to give the coefficient of the y- term (- 1)

The factors are - 5 and + 4, since

- 5 × 4 = - 20 and - 5 + 4 = - 1, thus

y² - y - 20 = (y - 5)(y + 4) ← in factored form

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Under a dilation, triangle XYZ where X(4, 7), Y(-3, 8), and Z(-2, -1) becomes triangle X’Y’Z’ where X’(12, 21), Y’(-9, 24), and

-BARSIC- [3]

It is 3, the points are all 3 times greater

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3 years ago

If (-1,4) and (3,-2) are end points of diameter of the circle, then the equation of the circle is

Volgvan

Answer:

If you've more doubts you can ask :)

Step-by-step explanation:

If the centre of a circle is (a, b) and radius r, then the equation of the circle is :

$(x - x)^2 + (y-b)^2 = r^2$

First we will find the centre, (a , b):

$a = \frac{3+(-1)}{2} = \frac{2}{2} = 1\\\\b = \frac{-2 + 4}{2} = \frac{2}{2} = 1$

Find radius:

$Radius, r = \frac{Diameter}{2}$

Diameter is the distance between (-1, 4) and (3, -2)

$diameter = \sqrt{(x_2 - x_1)^2 +(y_2-y_1)^2} \\\\$

$= \sqrt{(3-(-1)^2 + (-2-4)^2} \\\\=\sqrt{16 + 36}\\\\=\sqrt{52}\\\\=\sqrt{4 \times 13}\\\\=2\sqrt{13} \ units$

Therefore , $r = \frac{2 \times \sqrt{13} }{2} = \sqrt{13} \ units$

Equation of the circle is :

$(x - 1)^2 +(y-1)^2 = 13$

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3 years ago

In the past year Jenny watched 44 movies that she thought were very good. She watched 55 movies over the whole year. Of the movi

igomit [66]

To solve this problem, we must divide the number of movies that Jenny thought were very good by the total number of movies she watched. This is because we are finding a percentage, which represents a part out of a whole that have a factor, which in this case is very good movies. First, we begin by dividing 44/55. Then, we realize that both the numerator and the denominator are divisible by 11, so if we divided them both by 11 that would simplify the fraction.

44/55 = 44/11 / 55/11 = 4/5

Next, we can now easily divide our simplified fraction.

4/5 = 0.8

Finally, we must multiply by 100, because a percentage is a portion of 100 (the total is 100%). This is equivalent to moving the decimal point two places to the right.

0.8 * 100 = 80%

Therefore, Jenny thinks that 80% of the movies she watched this year were very good.

Hope this helps!

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3 years ago

18m-9v+6v-7m hope you can help

Valentin [98]

Here, you have to combine like terms. So, it is 11m-3v.

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4 years ago

Read 2 more answers

The height of a desk is 11 inches shorter than the height of a chair. The height of the chair is 41 inches.

defon

Answer:

equation: y=41-11

answer: the desk is 30 inches.

Step-by-step explanation:

So if the desk is 11 inches SHORTER than the chair, and the height of the chair is 41 inches, all you need to do is subtract 11 from 41, which will give you a total of 30 inches.

Hope this helps!

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3 years ago

Read 2 more answers