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Where do I place the coordinates for -2x-5 and -x-4

Where do I place the coordinates for -2x-5 and -x-4-example-1
User Miriam
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1 Answer

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9 votes

Explanation:

you need to calculate coordinates first. just by having the function definitions you don't have any coordinates yet.

I typically pick x = 0 as a first point.

so, that gives

-2×0 - 5 = -5

as y result for the first line.

the point on line 1 is then (0, -5)

and we get -0 - 4 = -4 as y result for the second line.

the point for the second line is (0, -4)

for second points I typically go for x = 1.

for the first line we get

-2×1 - 5 = -2 - 5 = -7

and the second point is (1, -7) for the first line.

for the second line we get

-1 - 4 = -5

and the second point is (1, -5) for the second line.

so, make points on the chart for all 4 points, and connect them (and extend the connecting lines to the left and right to the end of the grid).

and the crossing point ?

that is where both equations deliver the same result.

so,

-2x - 5 = -x - 4

-x = 1

x = -1

and the y is then e.g. -2×-1 - 5 = 2 - 5 = -3

and the crossing point is (-1, -3)

User Maged Saeed
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3.1k points