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Select the inequality that corresponds to the figure:

A.2x + y < 7

B. 2x - y < 7

C. 2x - y > -7

D. None of the above.

Select the inequality that corresponds to the figure: A.2x + y < 7 B. 2x - y &lt-example-1
User Coastline
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1 Answer

5 votes

Answer:

C. 2x-y>-7

Explanation:

The Line is not part of the region since is drawn in the graph using a dotted line, but we still need to find its equation.

The equation of a line is y=mx+b, where 'm' is the slope.

'm' can be obtained using the following formula.


m=(y_(2)-y_(1))/(x_(2)-x_(1))

To find the slope, as well 'b' we need points from the line, those will be (-6,-5), (0,7) as (x2,y2) and (x1,y1) respectively

Evaluating those point in the formula we have 'm' =2

Using now the above result and the point (0,7) in the equation y=mx+b, we obtain the value for 'b'.

7=2*0+b7

b=7

Hence our line is y=2x+7, and if we write it in standard form we obtain the following> y-2x=7.

Now, since our line is not part of the region, and the region is below that line, there is the < sign.

Hence the inequality that corresponds to the figure is y-2x<7 or, if we multiply by -1 (changin orientation of signs) 2x-y>-7

User Marcel Jaeschke
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