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What is the equation of a line, in general form that passes through point (1,-2) and had a slope of 1/3

3x-y-7=0
X-3y+7=0
X-3y-7=0

User Pcalcao
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2 Answers

3 votes
Third option.

Use y = mx + b (slope-intercept form) to get

y = (1/3)x + b.

Then plug in the point (1,-2) for x and y to figure out b...

-2 = (1/3)(1) + b

-2 - 1/3 = b, so b = -7/3

Now you have y = (1/3)x - 7/3. Convert to standard form by multiplying each term by 3 to get

3y = x - 7. Then move the 3y to the other side to get 0 = x - 3y - 7

5 votes

Answer:
x-3y+7=0

Explanation:

The equation of line passing from point (a,b) and has slope m is given by :-


(y-b)=m(x-a)

Given : Point = (1,-2)

Slope of line=
(1)/(3)

Now, the equation of a line that passes through point (1,-2) and had a slope of
(1)/(3) will be :-


(y-(-2))=(1)/(3)(x-1)\\\\\Rightarrow\ 3(y+2)=x-1\\\\\Rightarrow\ 3y+6=x-1\\\\\Rightarrow\ x-3y+7=0

Hence, the equation of a line, in general form that passes through point (1,-2) and had a slope of
(1)/(3) is
x-3y+7=0

User Surya KLSV
by
9.4k points