Question 736908: find the equation of the line that contains the point (3,-6) and has the same slope as the line 4x-y=5
Answer by MathLover1(20850)   (Show Source):
You can put this solution on YOUR website!
to find the equation of the line that contains the point ( , ) and has the   as the line  , first find
....solve for 
 .......this is  form  ;so, slope is 
now find the equation of the line that contains the point (,) and has the slope
| 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, -6)
- it has a slope of 4
First, let's draw a diagram of the coordinate system with point (3, -6) 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=4, 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:
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