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3 years ago

HELP!!! Solve the system of equation by graphing : y=x+3 , 2x+y= -6 : also how do you know if it’s substitution or elimination?

Mathematics

2 answers:

Alexxx [7]3 years ago

8 0

It’s substitution you can’t do elimination

schepotkina [342]3 years ago

4 0

Either would work, but substitution looks a bit easier.

The graph for these two is shown below.

I just put the equations in just as they are written. They did not have to be changed in any way. DESMOS is a wonderful program. Very powerful.

The blue line is 2x + y = - 6

The red line is y = x + 3

The best way to solve this other than a graph is to use substitution. Put the red graph into the blue one.

2x + y = - 6

2x +(x + 3) = - 6

2x + x + 3 = - 6

3x + 3 = - 6 Subtract 3 from both sides.

3x = - 6 - 3

3x = - 9

x = -9/3

x = -3

Now go back and solve for y

y = x + 3

y = -3 + 3

y = 0

Answer

The solution point is (-3,0) just what the graph shows.

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yulyashka [42]

Answer:

Step-by-step explanation:

From the given information;

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If each plate costs $20 to make, then the total number of plate will equal to 40x

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The total cost can be computed as:

$C(x) = (\dfrac{100}{x}) \times 125 + 20 x --- (1)$

$C'(x) = (-\dfrac{12500}{x^2}) + 20 --- (2)$

At C'(x) = 0

$\dfrac{12500}{x^2} = 20$

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$x^2= 625$

$x = \sqrt{625}$

x = 25

$C'' (x) = -12500 \times \dfrac{-2}{x^3} +0$

$C'' (x) = \dfrac{25000}{x^3}$

where; x = 25

$C'' (x) = \dfrac{25000}{25^3}$

C''(x) = 1.6

Thus, at x = 25, C'' > 0

As such, to minimize the cost, the printer needs to make 25 metal plates.

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3 years ago

Drag the point on the coordinate plane to the solution of the system of equations shown below: y=-2x-1 y = x + 2

Sveta_85 [38]

Answer:

(1,-1)

Step-by-step explanation:

-2x-1 = x+2

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x = -1

substitute

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point: (1,-1)

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3 years ago

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Answer:

Step-by-step explanation:

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Read 2 more answers

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Otrada [13]

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emmasim [6.3K]

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