In Exercises 79–80, find the value of y if the line through the t...

Question

In Exercises 79–80, find the value of y if the line through the two given points is to have the indicated slope. (3, y) and (1, 4), m = −3

Accepted Answer

Hey everyone here we are asked to use the given data to find the value of X. So we're given the point X. Three and the 30.2 X one. And were also given the fact that this slope is equal to negative two. So to solve this problem, we need to use the slope formula which tells us that slope M is equal to the quantity of Y sub two minus Y sub one divided by the quantity of Y X sub two minus X. Sub one. And so from here we just need to assign each X one, Y one and X up to Y sub two to either point. So I'm going to let the first point B X sub one and Y sub one. So then that means our second point must be except two and Y sub two. And just to note that it doesn't matter which point is assigned to what this is just what I decided to go with. So now we can plug in this information into the slope formula. So we have in the numerator, Y sub two which is one minus Y sub one which is three. And in the denominator we have X sub two which is two X minus X. Sub one, which is just X. And simplifying, we get one minus three is negative two divided by two X minus X which is just X. And now we can take this found slope which is negative two divided by X. And equate it to our given slope and we can do this because we know that our given points lie on the line with this given slope of negative two. So from here we can just start solving for X. So multiplying X to the other side, we get negative two is equal to negative two X. And now to get X alone, we're going to divide each side by negative two. So we get that X is equal to one, which is our answer here for choice. A thanks for watching. I hope you found this video helpful and I'll see you again next time.

In Exercises 79–80, find the value of y if the line through the two given points is to have the indicated slope. (3, y) and (1, 4), m = −3

Key Concepts

Slope of a Line

Point-Slope Form

Coordinate Geometry

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