Question 95728: Find the equation of the line that goes through the given point and has the given slope. Write the answer in slope-intercept form.
22. (-1, -5), -8
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! To solve this problem, you can start with the slope-intercept form of a linear equation. This
form is:
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y = mx + b
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where m is the slope and b is the value of y where the graph crosses the y-axis.
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In this problem you are told that the slope of the graph is -8. So in the slope-intercept
form you can replace m with -8. When you make that substitution, the equation becomes:
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y = -8x + b
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The problem tells you that the point (-1,-5) satisfies the equation. This means that the
equation is satisfied if x = -1 and y = -5. Substitute -1 for x and -5 for y to make the
equation become:
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-5 = -8(-1) + b
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Multiply on the right side and the equation and the equation becomes:
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-5 = +8 + b
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Subtract 8 from both sides to get rid of the 8 on the right side. This subtraction
makes the equation become:
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-13 = b
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Now that you know b is -13 and that m is -8, you can substitute these values into the
slope intercept form and the equation becomes:
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y = -8x - 13
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This is the equation that incorporates the information you were given and is in slope intercept
form.
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Hope this helps you to understand the problem and how to work out the answer.
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