178k views
1 vote
3. Find the value of r so the line that passes through (7,r) & (1, -1), has a slope ofm=į (9 pts)Hi can Someone please help !

User Petesiss
by
6.3k points

1 Answer

0 votes

You have the following points:

(7,r)

(1,-1)

and you have to find the value of r, that makes that the line which crosses the previous points has a slope of m = 1/2.

To find the value of r, you use the following formula for the slope m:

m = (y2 - y1)/(x2 - x1)

where (x1,y1) and (x2,y2) are two point of the line.

The points are:

(x1,y1) => (1,-1)

(x2,y2) => (7,r)

replace the previous values in the formula for the slope m, and solve for r:

m = (r - (-1))/(7 - 1)

m = (r + 1)/(6) multiply both sides by 6

6m = r + 1 subtract both sides by 1

6m - 1 = r replace the value of m = 1/2

6(1/2) - 1 = r

3 - 1 = r

2 = r

Hence, the value of r has to be r = 2 for getting a slope of m = 1/2 of a line which crosses the given points

User David Barry
by
7.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.