347,717 views
1 vote
1 vote
What is the equation in point-slope form of the line passing through (1,9) and (-1, 11)? (6 points)

Oy+9= -(x-1)
Oy-9=1(x+1)
Oy+9=1(x+1)
Oy-9=-(x-1)

User Natdico
by
3.1k points

2 Answers

23 votes
23 votes

Answer:

Explanation:

Point slope form:

y-y1=m(x-x1)

m=slope

(x1,y1)

First we need to find the slope using the slope formula:

y2-y1/x2-x1= slope

Given the two coordinates:

(1, 9) and (−1, 11)

Plug them into the slope formula:

11-9=2/-1-1=-2

Simplify:

2/-2=-1

Now we know that:

m=-1 and the (x1,y1) would be (1, 9)

Now we simply plug in the info:

y-9=-(x-1)

Final answer: y − 9 = −(x − 1)

User Willbt
by
3.3k points
4 votes
4 votes

Answer:


\sf D. \quad y-9=-(x-1)

Explanation:

First, find the slope of the line passing through the given points (1, 9) and (-1, 11):


  • \sf \textsf{let}\:(x_1,y_1)=(1,9)

  • \sf \textsf{let}\:(x_2,y_2)=(-1,11)


\implies \sf \textsf{slope}\:(m)=(y_2-y_1)/(x_2-x_1)=(11-9)/(-1-1)=-1

Point-slope form of linear equation


\sf y-y_1=m(x-x_1)

where:

  • m is the slope
  • (x₁, y₁) is a point on the line

Substitute the found slope and the point (1, 9) into the formula:


\implies \sf y-9=-1(x-1)


\implies \sf y-9=-(x-1)

User Chris Smeal
by
3.2k points