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Question 82830: write the standard form of the equation:
through (-1,-3) perpendicular to y=-1/5x +5
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! Since the slope of the given line is  , the perpendicular slope is the negative reciprocal of the given slope. So the perpendicular slope is  or just 5.
So lets find the equation of the line with a slope of 5 and goes through (-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, -3)
- it has a slope of 5
First, let's draw a diagram of the coordinate system with point (-1, -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=5, 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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