56.4k views
4 votes
Find the value of k so that the line through points (-3, 2k) and (k,6) has a slope of 4

1 Answer

5 votes

Answer:

-1

Explanation:

To find the slope, I'm going to line up the points and subtract.

I will then put 2nd difference over first difference.

( -3 , 2k)

-( k , 6)

-----------------

-3-k , 2k-6

So the slope in terms of k is:


(2k-6)/(-3-k).

We are also given the slope is 4 or 4/1.

This means we have the following equation to solve for k such that the slope is 4:


(2k-6)/(-3-k)=(4)/(1)

Cross multiply:


1(2k-6)=4(-3-k)

Distribute:


2k-6=-12-4k

Add 4k on both sides:


6k-6=-12

Add 6 on both sides:


6k=-6

Divide both sides by 6:


k=-1

So k has to have a value of -1 for the slope to be 4.

Let's check:

(-3,-2)

(-1,6)

--------Subtracting

-2,-8

So -8/-2 is 4.

The check is good and the value for k as -1 as been verified.

User DaveIdito
by
7.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories