Question 1182458: Determine whether each ordered pair is a solution to the inequality y>−5x+4
(−5,2)
(−4,−10)
(8,6)
(4,1)
(6,−3)
Found 2 solutions by ikleyn, math_tutor2020:
Answer by ikleyn(52814)   (Show Source):
You can put this solution on YOUR website! .
Hello, you just posted at least 3 (three, THREE) the same type problems and obtained at least 4 (four)
answers/explanations from the tutors.
This your post is just n4 in this row.
How many times we, the tutors, should explain/repeat you simple thing/things
in order for you finally get the method of solution ?
7 ? 19 ? 21 ? ? ?
Answer by math_tutor2020(3817)  (Show Source):
You can put this solution on YOUR website!
Let's plug in x = -5 and see what happens
y > -5x+4
y > -5(-5)+4
y > 25+4
y > 29
So if x = -5, then the y value is something larger than 29.
But that clashes with the y coordinate of choice A since we have y = 2 here.
Put another way, let's plug in the x,y coordinates of point A to find that...
y > -5x+4
2 > -5(-5)+4
2 > 25+4
2 > 29
and the contradiction is probably more clear by this point. We have a false statement at the end, so the original inequality is false when (x,y) = (-5,2). Choice A is ruled out as an answer.
Choice B is a similar story as choice A, so we rule that out as well.
Let's try choice C to find out what happens
y > -5x+4
6 > -5(8)+4
6 > -40+4
6 > -36
we get a true statement this time, so choice C is a solution. You should find choices D and E are also solutions.
Graph of y > -5x+4
The solution points are in the blue shaded region. If a point is on the boundary, then it is NOT a solution. The dashed boundary line is y = -5x+4 and it goes through (0,4) and (2,-6)
Check out this similar problem
https://www.algebra.com/algebra/homework/expressions/expressions.faq.question.1182457.html
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