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Write an equation in point-slope form that has a slope of -1/2 and a y-intercept of -8.

im confused

User Callmetwan
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1 Answer

4 votes

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Answer:

y +8 = -1/2x

Explanation:

The point-slope form of the equation for a line is ...

y -k = m(x -h) . . . . . . . line through point (h, k) with slope m

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The y-intercept point has an x-coordinate of 0, so that point is (0, -8). Filling in the values (h, k) = (0, -8) and m = -1/2 in the above form gives ...

y +8 = -1/2x . . . . . point-slope form of the equation

_____

Additional comment

Normally, given a slope and a y-intercept, you would use the slope-intercept form:

y = mx +b . . . . . . line with slope m and y-intercept b

y = -1/2x -8

You will notice the two forms of the equation are just different forms of the same thing. If you add 8 to both sides of the slope-intercept equation, you get the point-slope equation.

User Samuel Cook
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