the line pass through, m(-2,a), n(a,4), the slope is -1/2, what is the a?

Answer 1

Hello, thank you for taking the time to post your question!

The underlying equation that you want to use here is the slope formula: m=(y2​−y1​)/(x2​−x1​)

For this set of values, we have the points (−2,a) and (a,4) and a slope of −1/2.

Plugging these values into the slope formula gives you:

−1/2=(4−a)/(a−(−2))

−1/2=(4−a)/(a+2)

Now you can solve for a:

−1(a+2)=2(4−a)

−a−2=8−2a

a=10

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

slope = "rise over run" or change in y coordinates over change in x coordinates = (a-4)/(-2-a) = -1/2

cross multiply to get

2(a-4) = 2+a

2a -8 = 2+a

a = 10