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1. Which point is NOT on the graph represented by y = x^2 + 3x - 6? A. (-6, 12) B. (-4,-2) C. (2,4) D. (3,-6)2. What is an equation of the line that passes through (-2,3) and (6,-1)?

User Oscar Boykin
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1 Answer

4 votes
4 votes

If a point is in the graph of the parabola it needs to satisfy the equation. So we just need to find which values does not satisfy the equation


(-6)^2+3(-6)-6=12,

then the number A. IS on the graph


(-4)^2+3(-4)-6=-2,

then the number B. IS on the graph


(2)^2+3(2)-6=4,

then the number B. IS on the graph, and finally


(3)^2+3(3)-6=12,

since this is diferent from -6, then (3,-6) is NOT on the graph. Then the answer is D. (3,-6)

The point-slope form is


y-a=m(x-a)

we find the slope using the formula


m=(-1-3)/(6-(-2))=(-4)/(8)=-(1)/(2)

Replacing this, and the point (-2,3)


\begin{gathered} y-(-2)=-(1)/(2)(x-3) \\ y+2=-(1)/(2)x+(3)/(2) \\ 2y+2=-x+3 \\ x+2y=1 \end{gathered}

The equation of the line is x+2y=1

User Mreferre
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