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| Question 399387:  1.  What is the equation of a line that passes through points (-1, 2) and (5, 2)?
 y - 2 = 0
 x - 2 = 0
 y - x - 2 = 0
 2.  What is the equation of a line with a slope of -2 and a y-intercept of 8?
 x + 2y - 8 = 0
 2x + y - 8 = 0
 2x - y + 8 = 0
 3.  What is the slope of a line parallel to the line whose equation is y - x = 5?
 -1
 1
 5
 4.  What is the equation of the line that passes through the point (1, 1) and has a y-intercept of 2.
 x - y + 2 = 0
 x + y - 2 = 0
 x - y - 2 = 0
 5.  The slope of a line is 1/3 . What is the slope of a line perpendicular to this line?
 -3
 -1/3
 1/3
 3
 6.  What is the slope of a line perpendicular to the line whose equation is y = 2x + 5?
 slope = -1
 slope = -1/2
 slope = -2
 7.  What is the equation of a line with a point (-3, 0) and no slope?
 x + 3 = 0
 y + 3 = 0
 x - 3 = 0
 y - 3 = 0
 8.  What is the equation of a line that passes through point (1, -2) and has a slope of 1/3 .
 3x - y - 7 = 0
 x - 3y + 7 = 0
 x - 3y - 7 = 0
 9.  What is the equation of the line whose y-intercept is 3 and slope is 1?
 y = x - 3
 y = x + 3
 y = 3x + 1
 Found 2 solutions by  ewatrrr, MathLover1:
 Answer by ewatrrr(24785)
      (Show Source): 
You can put this solution on YOUR website! Hi
 1. What is the equation of a line that passes through points (-1, 2) and (5, 2) y = 2
 7. What is the equation of a line with a point (-3, 0) and no slope? x = -3
 
   
   2. What is the equation of a line with a slope of -2 and a y-intercept of 8?
 y = -2x + 8
 3. What is the slope of a line parallel to the line whose equation is y - x = 5?
 y = x+ 5   parallel lines have equal slopes of m = 1
 4. What is the equation of the line that passes through the point (1, 1) and has a y-intercept of 2.
 y = mx + 2
 1 = m + 2    m = -1
 y = -x + 2
 5. The slope of a line is 1/3 . What is the slope of a line perpendicular to this line?
 ⊥ Lines have slopes that are negative reciprocals of one another:  m = - 3/1
 6. What is the slope of a line perpendicular to the line whose equation is y = 2x + 5?  m =  -1/2
 8. What is the equation of a line that passes through point (1, -2) and has a slope of 1/3 .
 y = (1/3)x + b
 -2 = 1/3 + b
 -7/3 = b
 y = (1/3)x -7/3
 
Answer by MathLover1(20850)
      (Show Source): 
You can put this solution on YOUR website! 1. 
 
 | Solved by pluggable solver: Finding the Equation of a Line |  | First lets find the slope through the points (  ,  ) and (  ,  ) 
 
 
  Start with the slope formula (note: (  ,  ) is the first point (  ,  ) and  (  ,  ) is the second point (  ,  )) 
 
 
  Plug in  ,  ,  ,  (these are the coordinates of given points) 
 
 
  Subtract the terms in the numerator  to get  .  Subtract the terms in the denominator  to get  
 
 
 
 
  Reduce 
 
 
 So the slope is
 
 
  
 
 
 
 
 ------------------------------------------------
 
 
 Now let's use the point-slope formula to find the equation of the line:
 
 
 
 
 ------Point-Slope Formula------
 
  where  is the slope, and (  ,  ) is one of the given points 
 
 So lets use the Point-Slope Formula to find the equation of the line
 
 
 
  Plug in  ,  , and  (these values are given) 
 
 
 
  Rewrite  as  
 
 
 
  Distribute  
 
 
  Multiply  and  to get  . Now reduce  to get  
 
  Add  to  both sides to isolate y 
 
 
  Combine like terms  and  to get   
 ------------------------------------------------------------------------------------------------------------
 
 Answer:
 
 
 
 So the equation of the line which goes through the points (
  ,  ) and (  ,  )  is:  
 
 The equation is now in
  form (which is slope-intercept form) where the slope is  and the y-intercept is  
 
 Notice if we graph the equation
  and plot the points (  ,  ) and (  ,  ),  we get this: (note: if you need help with graphing, check out this solver) 
 
 
  Graph of  through the points (  ,  ) and (  ,  ) 
 
 Notice how the two points lie on the line. This graphically verifies our answer.
 
 
 
 |  
 
 answer:
  or in slope-intercept form   
 2.
 
 
 | Solved by pluggable solver: FIND a line by slope and one point |  | What we know about the line whose equation we are trying to find out:
 
 
 it goes through point (0, 8)
 it has a slope of -2
 
 First, let's draw a diagram of the coordinate system with point (0, 8) plotted with a little blue dot:
 
 
  
 Write this down: the formula for the equation, given point
  and intercept a, is 
 
  (see a paragraph below explaining why this formula is correct) 
 Given that a=-2, and
  , we have the equation of the line: 
 
  
 Explanation: Why did we use formula
  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (  ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (  ,  ):  Here, we know a,  , and  , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  . 
 Here's the graph:
 
 
  
 |  
 
 answer:
  or in slope-intercept form   
 3.
 
  or   
 
 
 | Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc |  | Equation  describes a sloping line. For any equation ax+by+c = 0, slope is
  . X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x =  c/a. 5/-1 = -5.Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 5/1 = 5.Slope is --1/1 = 1. Equation in slope-intercept form: y=1*x+5.
   |  
 answer: slope is
   
 4.
 
 
 | Solved by pluggable solver: FIND EQUATION of straight line given 2 points |  | hahaWe are trying to find equation of form y=ax+b, where a is slope, and b is intercept, which passes through points (x1, y1) = (1, 1) and (x2, y2) = (0, 2). Slope a is
  . Intercept is found from equation
  , or  . From that, intercept b is
  , or  . 
 y=(-1)x + (2)
 
 Your graph:
 
 
  
 |  
 
 answer:
  or in slope-intercept form   
 
 5.
 if slope of the one line is
  , the slope of perpendicular line will be   
 so, if
  , the slope of perpendicular line will be   
 6.
 equation
  is already in slope-intercept form and you can see that slope is  ; so, the slope of a line perpendicular to this line will be   
 7.
 
 
 
 | Solved by pluggable solver: FIND a line by slope and one point |  | What we know about the line whose equation we are trying to find out:
 
 
 it goes through point (-3, 0)
 it has a slope of 0
 
 First, let's draw a diagram of the coordinate system with point (-3, 0) plotted with a little blue dot:
 
 
  
 Write this down: the formula for the equation, given point
  and intercept a, is 
 
  (see a paragraph below explaining why this formula is correct) 
 Given that a=0, and
  , we have the equation of the line: 
 
  
 Explanation: Why did we use formula
  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (  ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (  ,  ):  Here, we know a,  , and  , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  . 
 Here's the graph:
 
 
  
 |  
 
 8.
 the equation of a line that passes through point (1, -2) and has a slope of 1/3
 
 
 
 | Solved by pluggable solver: FIND a line by slope and one point |  | What we know about the line whose equation we are trying to find out:
 
 
 it goes through point (1, -2)
 it has a slope of 0.333333333333333
 
 First, let's draw a diagram of the coordinate system with point (1, -2) plotted with a little blue dot:
 
 
  
 Write this down: the formula for the equation, given point
  and intercept a, is 
 
  (see a paragraph below explaining why this formula is correct) 
 Given that a=0.333333333333333, and
  , we have the equation of the line: 
 
  
 Explanation: Why did we use formula
  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (  ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (  ,  ):  Here, we know a,  , and  , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  . 
 Here's the graph:
 
 
  
 |  
 you got:
 
  ...or in slope-intercept form   
  ...or in slope-intercept form   or
   
 
  ...or in slope-intercept form  or   so the answer is :
   9.
 
 
 | Solved by pluggable solver: FIND a line by slope and one point |  | What we know about the line whose equation we are trying to find out:
 
 
 it goes through point (0, 3)
 it has a slope of 1
 
 First, let's draw a diagram of the coordinate system with point (0, 3) plotted with a little blue dot:
 
 
  
 Write this down: the formula for the equation, given point
  and intercept a, is 
 
  (see a paragraph below explaining why this formula is correct) 
 Given that a=1, and
  , we have the equation of the line: 
 
  
 Explanation: Why did we use formula
  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (  ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (  ,  ):  Here, we know a,  , and  , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  . 
 Here's the graph:
 
 
  
 |  
 
 so the answer is :
   
 
 
 
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