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Write an equation that goes through (1,-2) and is parallel to y + 2=3(x - 1)

User Rkellerm
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1 Answer

3 votes

Answer:

y= 3x -5

Explanation:

The equation of a line is usually written in the form of y=mx+b, where m is the gradient and b is the y-intercept.

Let's rewrite the equation of the given line in the form of y=mx+b, so we can find its gradient.

y +2= 3(x -1)

y +2= 3x -3 (expand)

y= 3x -3 -2

y= 3x -5

Gradient of given line= 3

Gradient of unknown line= 3,

since parallel lines have the same gradient.

Susbt. m=3 into the equation:

y= 3x +b

Substitute a coordinate to find the value of b.

When x= 1, y= -2,

-2= 3(1) +b

-2= 3 +b

b= -2 -3 (-3 on both sides)

b= -5 (simplify)

Thus the equation of the line is y= 3x -5.

User Colin Goudie
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