SOLUTION: Write the equation of the line given: a. m= -1/2 though (2,4) b. Through (1,5) & (-2,1)

Algebra ->  Linear-equations -> SOLUTION: Write the equation of the line given: a. m= -1/2 though (2,4) b. Through (1,5) & (-2,1)      Log On


   

Question 58620: Write the equation of the line given:
a. m= -1/2 though (2,4)
b. Through (1,5) & (-2,1)
Found 2 solutions by checkley71, funmath:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
m=-1/2 through (2,4)
Y=mX+b
4=-1/2*2+b
4=-1+b
b=4+1
b=5
Y=-1/2X+5
SLOPE IS
(1-5)/(-2-1)=-4/-3=4/3
5=4/3*1+b
5=4/3+b
b=5-4/3
b=11/3

Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
Write the equation of the line given:
a. m= -1/2 though (2,4)
One way to do this is to use the point slope formula: highlight%28y-y1=m%28x-x1%29%29, where m=slope, (x1,y1)=given point.
m=-1/2 and (x1,y1)=(2,4)
y-4=%28-1%2F2%29%28x-2%29
y-4=%28-1%2F2%29x-%281%2F2%29%28-2%29
y-4=%28-1%2F2%29x%2B1
y-4%2B4=%28-1%2F2%29x%2B1%2B4
y=%28-1%2F2%29x%2B5 slope intercept form of a line.
:
b. Through (1,5) & (-2,1)
You need to find the slope between the two points using the slope formula:highlight%28m=%28y2-y1%29%2F%28x2-x1%29%29
(x1,y1)=(1,5) and (x2,y2)=(-2,1)
m=%281-5%29%2F%28-2-1%29
m=-4%2F-3
m=4%2F3
Now that you have a slope and a point you can find the equation of the line using the point slope formula. m=4/3, (x1,y1)=(1,5)
y-5=%284%2F3%29%28x-1%29
y-5=%284%2F3%29x-%284%2F3%29
3%28y-5%29=3%284%2F3%29x-3%284%2F3%29
3y-15=4x-4
3y-15%2B15=4x-4%2B15
3y=4x%2B11
-4x%2B3y=-4x%2B4x%2B11
-4x%2B3y=11
-%28-4x%2B3y%29=-11
4x-3y=-11 Standard form of a line.
Happy Calculating!!!