Find the equation of the line with slope = -2 and passing through (-3,-9). Write your equation in point-slope AND slope-intercept forms.

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MsRay

Answer:

Point-slope form:  (y + 9) = -2(x +3)

Slope-intercept form:  y = -2x - 15

Step-by-step explanation:

It is important to know the formula for both point-slope (y - y,) = m(x - x,) and slope-intercept form (y = mx +b).  In both cases 'm' represents the slope.  In the question, slope = -2 and the point (-3, -9) is given which is the (x, y) values.  We can first complete the point-slope form by plugging in the given values:  (y - (-9)) = -2(x- (-3)) this can then be simplified to:  (y + 9) = -2(x +3).  However, in order to complete the slope-intercept form, we need to fill in the m, x and y variables and solve for 'b':  -9 = -2(-3) + b or -9 = 6 + b, we then subtract 6 from both sides:  -9 - 6 = 6 - 6 + b to get -15 = b.  We then place our slope and y-intercept into the equation:  y = -2x - 15.