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2 years ago

8x+9y=-28 -4x=y solve the system by subsitution

Mathematics

2 answers:

bixtya [17]2 years ago

8 0

Answer:

x= 1

y = -4

Step-by-step explanation:

8x + 9y = -28

-4x = y

8x + 9(-4x) = -28

8x - 36x = -28

-28x = - 28

x = 1

y = -4(1) = -4

Zielflug [23.3K]2 years ago

6 0

Answer:

Step-by-step explanation:

8 + 9 = 17

17y = 28

28 / 17 = 1.64

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ohaa [14]

Given:
speed = distance / time

walking: 3 miles per hour
running 5 miles per hour
for a total of 3 hours.

3t = 5(3-t)
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t = 1 7/8

7/8 * 60 mins = 52.50 minutes

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3 years ago

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Which of the following equations have complex roots?

mestny [16]

Answer:

Step-by-step explanation:

Complex roots of quadratic functions occur when the <u>discriminant is negative</u>.

<u>Discriminant</u>

$b^2-4ac\quad\textsf{when}\:\:ax^2+bx+c=0$

Evaluate the discriminant of each of the given equations.

$\textsf{A.} \quad 3x^2+2=0$

$\implies a=3, \quad b=0, \quad c=2$

$\implies b^2-4ac=0^2-4(3)(2)=-24$

As -24 < 0 the equation will have complex roots.

$\textsf{B.} \quad 2x^2+1=7x$

$\implies 2x^2-7x+1=0$

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$\implies b^2-4ac= (-7)^2-4(2)(1)=41$

As 41 > 0 the equation does not have complex roots.

$\textsf{C.} \quad 3x^2-1=6x$

$\implies 3x^2-6x-1=0$

$\implies a=3, \quad b=-6, \quad c=-1$

$\implies b^2-4ac=(-6)^2-4(3)(-1)=48$

As 48 > 0 the equation does not have complex roots.

$\textsf{D.} \quad 2x^2-1=5x$

$\implies 2x^2-5x-1=0$

$\implies a=2, \quad b=-5, \quad c=-1$

$\implies b^2-4ac=(-5)^2-4(2)(-1)=33$

As 33 > 0 the equation does not have complex roots.

Learn more about discriminants here:

brainly.com/question/27444516

brainly.com/question/27869538

Learn more about complex roots here:

brainly.com/question/26344541

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2 years ago

Ini apa we jawabannya pelasee

kupik [55]

Answer:

<h3></h3><h2><u>kualitas terjemahannya mungkin tidak bagus. Jadi lihat 2 baris terakhir jika Anda tidak mengerti.</u></h2>

Jadi jumlah derajat tidak masalah. Mereka masih akan menempuh jarak yang sama.

Karena Anda mengatakan bahwa ekspres Marina berjalan pada 40 km / jam dan kami melakukan 2 jam. 40 * 2 = 80 km. Untuk Dumai Anda melakukan hal yang sama, 48 * 2 = 96.

Marina berjalan sejauh 80 km

Dumai berjarak 96 km

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3 years ago

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Vlad1618 [11]

There are many possible answers.
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3 years ago

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sammy [17]

Answer:(F/G)(x)=7

Step-by-step explanation:

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3 years ago