SOLUTION: need help to find the equation of the line which contains the point(2,1) and has slope 2

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Question 212518: need help to find the equation of the line which contains the point(2,1) and has slope 2
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
Need help to find the equation of the line which contains the point(2,1) and has slope 2

Step 1. The slope m is given as

m=%28y2-y1%29%2F%28x2-x1%29

Step 2. Let (x1,y1)=(2,1) or x1=2 and y1=1 . Let other point be ((x2,y2)=(x,y) or x2=x and y2=y.

Step 3. Now we're given m=2. Substituting above values and variables in the slope equation m yields the following steps:

m=%28y2-y1%29%2F%28x2-x1%29

2=%28y-1%29%2F%28x-2%29

Step 4. Multiply x-2 to both sides to get rid of denominator on right side of equation.

2%28x-2%29=y-1

2x-4=y-1

Step 5. Now add 1 to both sides of equation to solve for y.

2x-4%2B1=y-1%2B1

2x-3=y

Note: the above equation can be rewritten as
2x-y=3
And the graph is shown below which is consistent with the above steps.

Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation 2+x+%2B+-1+y+=+3 describes a sloping line. For any
equation ax+by+c = 0, slope is -a%2Fb+=+-2%2F-1.
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 3/2 = 1.5.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 3/-1 = -3.
  • Slope is -2/-1 = 2.
  • Equation in slope-intercept form: y=2*x+-3.
graph%28+500%2C+500%2C+1.5-8%2C+1.5%2B8%2C+-3-8%2C+-3%2B8%2C+2%2Ax%2B-3+%29+




I hope the above steps were helpful. Good luck in your studies!

Respectfully,
Dr J

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