Respuesta :
Hi student, let me help you out! :)
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We are asked to find the equation of the line, using the given information:
[tex]\star~\mathrm{-3}[/tex], which is the slope
[tex]\star~\mathrm{(1,2)}[/tex] which is a point that the line contains
[tex]\triangle~\fbox{\bf{KEY:}}[/tex]
- The slope is the number before x, in the form [tex]\mathtt{y=mx+b}[/tex].
Since "m" is the slope, and we're given what the slope is, we can substitute -3 for m:
[tex]\dag~\mathtt{y=-3x+b}[/tex]
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Now, we need to find the y intercept, "b", of the line.
Here's how it's done:
Remember the point that the line contains, (1,2)?
Well, its y-coordinate is 2; so what we do is substitute 2 for y:
[tex]\dag~\mathtt{2=-3x+b}[/tex]
Also, its x-coordinate is 1, so we substitute 1 for x:
[tex]\dag~\mathtt{2=-3(1)+b}[/tex]
Now, solve for b:
[tex]\dag~\mathtt{2=-3+b}[/tex]
Add 3 to both sides:
[tex]\dag~\mathtt{2+3=b}[/tex]
Thus, we have
[tex]\dag~\mathtt{5=b}[/tex]
Thus, the equation of the line is:
[tex]\bigstar\underline{\boxed{\mathtt{y=-3x+5}}}[/tex]
Hope it helps you out! :D
Ask in comments if any queries arise.
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