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2 years ago

Solve the following system of equations by Substitution. 5x + 4y = 7 -2x - 2y = 8

Mathematics

2 answers:

kolezko [41]2 years ago

7 0

Answer:

y = 9/13

Step-by-step explanation:

x = -4 + y

5(-4 + y) + 4y = 7

-20 + 9y = 7

9y = -13

mariarad [96]2 years ago

3 0

Answer:

5x + 4y = 7 × -2

-2x - 2y = 8 × 5

-10x - 8y = -14

-10x - 10y = 40

Step-by-step explanation:

2y = -54 ÷2

y = -27

Now substitute the value of y into equation (1)

5x + 4y = 7

5x + 4(-27) = 7

5x = 7 + 108

5x = 115

X = 23

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2 years ago

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2 years ago

Adina read 60 out of 100 pages in a comic book.Write the fraction of the pages she read in simplest form

Ad libitum [116K]

Answer:

3/5 is 60/100 in it's simplest form.

Step-by-step explanation:

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2 years ago

PLEASE HELP NOW!! If K is the set of all letters in the word “equation”, and L is the set of all letters of the word “inequality

satela [25.4K]

Answer:

e,q,u,a,t,i,n & EQUATIONYL

Step-by-step explanation:

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I N E Q U A L I T Y

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2 years ago

What are all of the real roots of the following polynomial? f(x) x^4-24x^2-25

Greeley [361]

<u>Answer:</u>

x = ±5

<u>Step-by-step explanation:</u>

We are given the following polynomial function and we are to find all of its real roots:

$x^4-24x^2-25$

Let $y=x^2$ so we can now write it as:

$y^2-24y-25$

Factorizing it to get:

$(y^2+y)+(-25y-25)$

$y\left(y+1\right)-25\left(y+1\right)$

$\left ( y + 1 \right ) \left ( y - 2 5 \right)$

Substitute back $y=x^2$ to get:

$\left ( x^2 + 1 \right ) \left ( x^2 - 25 \right )$

$\left ( x^2 + 1 \right ) \left ( x + 5 \right ) \left ( x - 5 \right )$

The quadratic factor has only complex roots. Therefore, the real roots are x = ±5.

3 0

3 years ago

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