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2. Find two ordered pairs that make the equation – 2x + y = 8 true. Show all work.

User MikeT
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2 Answers

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Answer:

(0, 8) and (-4, 0)

Explanation:

Equation is -2x + y = 8

Manipulate this equation so that it becomes a slope-intercept form of equation

To do this:

Add 2x on both sides

-2x + 2x + y = 2x + 8

y = 2x + 8

Once we have this, 2 points which definitely lie on the line are its x and y intercepts

This is the equation of a line with slope = 2 and x-intercept = 8

x-intercept is y-value when x = 0
We can check by plugging in 0 for x in y = 2x + 8

=> y = 2(0) + 8 = 8

=> Point(0, 8) is one of the ordered pairs

Similarly we can find the x-intercept by setting y = 0 and solving for x

Setting y = 0 in y = 2x + 8

=> 0 = 2x + 8

Switch sides

2x + 8 = 0

Subtract 8 from both sides

2x + 8 - 8 = 0 - 8

2x = -8

Divide both sides by 2

=> 2x/2 = -8/2

x = -4

So (-4, 0) is another point on the line

Two ordered pairs are therefore

(0, 8) and (-4, 0)

The attached graph shows you that it is indeed so

User Matt Blaha
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10 votes
10 votes
-2(-4) + 0 = 8
-2 x -4 = 8
8 + 0 = 8
Ordered pair: (-2, -4)

-2(-3) + 2 = 8
-2 x -3 = 6
6 + 2 = 8
Ordered pair: (-3, 2)

Hope this helps! :)
User Gandi
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3.1k points