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A line containing the points (3,0) and (-2,-2) is graphed on a coordinate grid. Which of these
points is a solution to the equation that represents this line?

(-12,-6)
(-4,-3)
(0.5,-1)
(5,0.8)
(9,3)
(18,6)

Respuesta :

Answer: (-12,-6)

Step-by-step explanation:

If we already have two points of the line, we can find its slope ([tex]m[/tex]), its intersection with the y-axis ([tex]b[/tex]), hence its equation:

Point 1: [tex](x_{1},y_{1})=(3,0)[/tex]

Point 2: [tex](x_{2},y_{2})=(-2,-2)[/tex]

Slope equation:

[tex]m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]

[tex]m=\frac{-2-0}{-2-3}[/tex]

[tex]m=\frac{2}{5}[/tex] This is the slope of the line

Now, the equation of the line is:

[tex]y=mx+b[/tex]

We already know the slope, now we have to find [tex]b[/tex] with any of the given points. Let's choose Point 1: [tex](x_{1},y_{1})=(3,0)[/tex]

[tex]0=\frac{2}{5}(3)+b[/tex]

Isolating [tex]b[/tex]:

[tex]b=-\frac{6}{5}[/tex]

Then, the equation of the line is:

[tex]y=\frac{2}{5} x-\frac{6}{5}[/tex]

With this equation we can find which point is a solution. Let's begin with the first point (-12,-6):

[tex]-6=\frac{2}{5} (-12)-\frac{6}{5}[/tex]

[tex]-6=-\frac{24}{5} -\frac{6}{5}[/tex]

[tex]-6=-6[/tex] Since both sides of the equation are equal, (-12,-6) is the point that fulfills the solution of the equation.

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