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Write the standard form of the line that passes through (-1,-3) and (2,1)

User Pastjean
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1 Answer

3 votes

Answer:

4x - 3y = 5

Explanation:

The equation of a line in standard form is

Ax + By = C ( A is a positive integer and B, C are integers )

First obtain the equation in point- slope form

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (- 1, - 3) and (x₂, y₂ ) = (2, 1)

m =
(1+3)/(2+1) =
(4)/(3)

Using (a, b) = (2, 1), then

y - 1 =
(4)/(3) (x - 2) ← in point- slope form

Multiply both sides by 3

3y - 3 = 4(x - 2) ← distribute and rearrange

3y - 3 = 4x - 8 ( add 8 to both sides )

3y + 5 = 4x ( subtract 3y from both sides )

5 = 4x - 3y, so

4x - 3y = 5 ← in standard form

User Manoj Purohit
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