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3 years ago

7x + 4y = 5 7x + 4y = 12

Mathematics

1 answer:

xz_007 [3.2K]3 years ago

5 0

Answer:

No answer

Step-by-step explanation:

Let's say I would like to eliminate x in order to find the value of y.So I multiply the second equation by (-1), but than I also eliminate y. Therefore, this system of equations doesn't have a solution.

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Select the correct answer from each drop-down menu.

erik [133]

Answer:

Grades 6 and 8

Step-by-step explanation:

If the relationship of girls to boys in two different grades are proportional, they must have the same ratio. To tackle this problem, we can find the ratios of genders in each grade and compare them.

Step 1, finding ratios:

Finding ratios is just like simplifying fractions. We will reduce the numbers by their greatest common factors.

GRADE 6:

$9:12=\\3:4$

GRADE 7:

$12:18=\\2:3$

GRADE 8:

$15:20=\\3:4$

GRADE 9:

$25:36$

Can't be simplified!

Step 2:

Notice how grades 6 and 8 both had a ratio of 3:4. We can conclude that these two grades have a proportional relationship between girls and boys.

I hope this helps! Let me know if you have any questions :)

8 0

2 years ago

Mr. See weights his grades. Tests are worth 60%, quizzes are worth 25% and homework is 15%. Joey's test average is an 82, his qu

goldenfox [79]

Answer:

83.15

Step-by-step explanation:

Joey's current grade can be determined by weighting his scores with the weights given and adding the results

Tests = 0.6 x 82 = 49.2

Quizzes = 0.25 x 77 = 19.25

homework = 0.15 x 98 = 14.7

49.2 + 19.25 + 14.7 = 83.15

4 0

2 years ago

A parachutist's speed during a free fall reaches 180 kilometers per hour. What is this speed in meters per second? At this speed

Darya [45]

Answer:

Speed of the parachutist is meters per second $2.083$ meter per second

Distance travelled in 2 seconds $4.167$ meter

Step-by-step explanation:

Speed of the parachutist is kilometers per hour = 180

Speed of the parachutist is meters per second $\frac{180*1000}{24*60*60} = 2.083$ meter per second

Distance travelled in 2 seconds $2.083 *2 = 4.167$ meter

8 0

2 years ago

Which of the following numbers is irrational?

Nastasia [14]

The believe the answer would be D.

7 0

2 years ago

1) Determine the discriminant of the 2nd degree equation below:

Aleksandr-060686 [28]

$\LARGE{ \boxed{ \mathbb{ \color{purple}{SOLUTION:}}}}$

We have, Discriminant formula for finding roots:

$\large{ \boxed{ \rm{x = \frac{ - b \pm \: \sqrt{ {b}^{2} - 4ac} }{2a} }}}$

Here,

x is the root of the equation.
a is the coefficient of x^2
b is the coefficient of x
c is the constant term

1) Given,

3x^2 - 2x - 1

Finding the discriminant,

➝ D = b^2 - 4ac

➝ D = (-2)^2 - 4 × 3 × (-1)

➝ D = 4 - (-12)

➝ D = 4 + 12

➝ D = 16

2) Solving by using Bhaskar formula,

❒ p(x) = x^2 + 5x + 6 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5\pm \sqrt{( - 5) {}^{2} - 4 \times 1 \times 6 }} {2 \times 1}}}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5 \pm \sqrt{25 - 24} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 5 \pm 1}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = - 2 \: or - 3}}}$

❒ p(x) = x^2 + 2x + 1 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm \sqrt{ {2}^{2} - 4 \times 1 \times 1} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm \sqrt{4 - 4} }{2} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - 2 \pm 0}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = - 1 \: or \: - 1}}}$

❒ p(x) = x^2 - x - 20 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - ( - 1) \pm \sqrt{( - 1) {}^{2} - 4 \times 1 \times ( - 20) } }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{ 1 \pm \sqrt{1 + 80} }{2} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{1 \pm 9}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = 5 \: or \: - 4}}}$

❒ p(x) = x^2 - 3x - 4 = 0

$\large{ \rm{ \longrightarrow \: x = \dfrac{ - ( - 3) \pm \sqrt{( - 3) {}^{2} - 4 \times 1 \times ( - 4) } }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{3 \pm \sqrt{9 + 16} }{2 \times 1} }}$

$\large{ \rm{ \longrightarrow \: x = \dfrac{3 \pm 5}{2} }}$

So here,

$\large{\boxed{ \rm{ \longrightarrow \: x = 4 \: or \: - 1}}}$

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5 0

2 years ago

Read 2 more answers