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What is the equation of this line in standard form?

6x−7y=11

6x−7y=−11

7x−6y=11

6x−5y=−13

What is the equation of this line in standard form? 6x−7y=11 6x−7y=−11 7x−6y=11 6x-example-1
User The Nightman
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1 Answer

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Answer:

(b) 6x −7y = −11

Explanation:

Perhaps the easiest way to approach this is to look at the y-intercept. To find it, set the value of x to zero, and divide by the y-coefficient. The y-intercepts of these equations are ...

a) 11/-7 = -1 4/7

b) -11/-7 = 1 4/7 . . . . possible candidate

c) 11/-6 = -1 5/6

d) -13/-5 = 2 3/5

The only y-intercept that matches the graph is the one for equation ...

6x -7y = -11

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You can use any of several other strategies to verify this choice:

1) Putting the given point values into the equation:

for (-3, -1): 6(-3) -7(-1) = -18 +7 = -11 . . . . yes

for (1/2, 2): 6(1/2) -7(2) = 3 -14 = -11 . . . . yes

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2) Finding the equation from the given points.

m = (y2 -y1)/(x2 -x1) = (2 -(-1))/(1//2 -(-3)) = 3/(3 1/2) = 6/7

Then the point-slope equation is ...

y -k = m(x -h) . . . . . . line with slope m through point (h, k)

y -(-1) = 6/7(x -(-3)) . . . . . substitute known values

7y +7 = 6x +18 . . . . multiply by 7, simplify

6x -7y = -11 . . . . . . . add -18 -7y to both sides

User Max Stewart
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