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4 years ago

2x - 7y = 2 and 3x + y = -20 addition/elimination

Mathematics

1 answer:

Mkey [24]4 years ago

6 0

Answer:

x = -6, y = -2

Step-by-step explanation:

2x-7y = 2

3x + y = -20

We need to cancel out either x or y to solve the equation. I'll cancel out x first

3(2x-7y = 2)

-2(3x+y=-20)

___________

6x-21y = 6

-6x -2y = 40

____________

-23y = 46

y = -2

Plug the value for y in one of the 2 equations to solve for x

2x -7(-2) = 2

2x+14=2

2x = -12

x=-6

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Answer:

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Step-by-step explanation:

Let first football player rushed x yards.

One football player rushed 4 times as many yards as the other, then the second player rushed 4x yars.

In total, they rushed

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4 years ago

Find the equation for the set of points whose distance from the y-axis equals the distance from the xz-plane.

julia-pushkina [17]

Answer:

$x_1^2 + z_1^2 = y_1^2$

Step-by-step explanation:

Let $p(x_1, y_1, z_1)$ be the point.

Any point on y-axis is (0, y, 0)

So, distance is

= $\sqrt{x_1^2+0 + z_1^2}$

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Now any point on x-z plane is $( x_1, 0, z_1 )$

Distance from p to this point is

= $\sqrt{0+y_1^2 + 0}$

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Equating (1) and (2), we get

$\sqrt{x_1^2 + z_1^2} = \sqrt{y_1^2}$

$x_1^2 + z_1^2 = y_1^2$

This is the required equation.

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3 years ago

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Answer:

Step-by-step explanation:

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