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Can someone please help me!

Can someone please help me!-example-1
User Kranzky
by
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1 Answer

6 votes

Answer:

D

Explanation:

Let's derive the equations for the two graphs;

For the graph towards the right,

The slope = y2-y1/x2-x1; so we choose two corresponding points (x1,y1); (x2,y2)

Let's choose points;

(2,1) and (3,2)

The slope = 2-1/ 3-2 = 1/1 = 1

From the general equation of a line

y = mx + c = 1× x + (-1) = x-1

y = x-1

Similarly for that towards the left we have;

The slope = y2-y1/x2-x1; so we choose two corresponding points (x1,y1); (x2,y2)

Let's choose points;

(2,1) and (3,2)

The slope = 2-1/ 3-2 = 1/1 = 1

From the general equation of a line

y = mx + c = 1× x + (-1) = x-1

y = x-1

Similarly for that towards the left we have;

The slope = y2-y1/x2-x1; so we choose two corresponding points (x1,y1); (x2,y2)

Let's choose points;

(-7,0) and (-4,-3)

Slope = -3-0/ -4-(-7) = -3/ 3 = -1

From the general equation of a line

y = mx + c = -1× x + c = -x + c

Since c is not obvious we can find the equation by picking just a point along the graph along side an arbitrary (x,y) point hence we have for slope;

If we pick (-7,0)

y-0 / x-(-7) = -1

y / x+7 = -1

y = -x -7

The equations of the graphed lines are;

y=x-1

y=-x-7

Look at option D you we see it's the same as the equation of the graph towards the right y=x-1

For the records

y=[x+3]-4 = x+3-4 = x-1

User David Perry
by
5.6k points