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Veronika [31]
3 years ago
12

2x + y = 7 5x + y = 9 Solve the system of equations.

Mathematics
2 answers:
kirza4 [7]3 years ago
5 0
The first step of solving a system of equations is to solve one equation for a variable. I'll solve the first one for y.

2x + y = 7                     Subtract 2x from both sides
        y = -2x + 7

Now, plug that y value into the y of the second equation and solve for x.

            5x + y = 9          Substitute
5x + (-2x + 7) = 9          Adjust the signs to get rid of parentheses
    5x - 2x + 7 = 9          Combine like terms
           3x + 7 = 9          Subtract 7 from both sides
                 3x = 2          Divide both sides by 3
                   x = \frac{2}{3}

Now, plug that into the first equation.

2x + y = 7     Substitute
2(\frac{2}{3}) + y = 7      Multiply
\frac{4}{3} + y = 7     Subtract \frac{4}{3} from each side
y = 5 \frac{2}{3}

The answer to the system of equations is (\frac{2}{3}, 5 \frac{2}{3}).


Naddika [18.5K]3 years ago
5 0
2x + y = 7
-                            Using elimination
5x + y = 9
__________
-3x + 0 = -2
__________

-3x = -2

x = -2/-3

x = 2/3

From 2x + y = 7,   substitute, x = 2/3

2*(2/3) + y = 7

4/3 + y = 7,    

y = 7 - 4/3

y = (21 - 4)/3 = 17/3

y = 17/3

x = 2/3,     and     y = 17/3
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Answer:

Mean of the data set in the dot plot would be: 3.6

Step-by-step explanation:

As we know that Mean from the dot plot can be obtained by:

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Please check the attached figure where the dot plot is also plotted.

From the dot plot, it is clear that

There are 3 dots at 1.

There are 4 dots at 2.

There are 3 dots at 3.

There are 4 dots at 4.

There are 5 dots at 5.

There are 3 dots at 6.

All we have to do is to add the dots and divide the sum by the number of addend dots.

In other words:

There are 3 dots at 1    ⇒  1+1+1

There are 4 dots at 2   ⇒  2+2+2+2

There are 3 dots at 3   ⇒   3+3+3

There are 4 dots at 4   ⇒   4+4+4+4

There are 5 dots at 5   ⇒   5+5+5+5+5

There are 3 dots at 6   ⇒   6+6+6

As there are total 22 dots.

And the sum of all the dots with respect to their plot number = 79

i.e. 1+1+1+2+2+2+2+3+3+3+4+4+4+4+5+5+5+5+5+6+6+6 = 79

Thus

Mean of the data set in the dot plot = 79/22

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Therefore, Mean of the data set in the dot plot would be: 3.6

4 0
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Klio2033 [76]

Answer:

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.20x + 81.6 - .68x = 69.6 ( add .20x and -.68x)

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