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Re: If line k in the xy-coordinate plane has the equation Ax + By = C, wha
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23 Jul 2018, 05:52

If line k in the xy-coordinate plane has the equation Ax + By = C, what is the slope of line k ?

(1) A = 2B \(Ax+By=C..........2Bx+By=C.........2x+y=\frac{C}{B}........y=-2x+\frac{C}{B}\)... Now this is in the form y=mx+C, where m is slope.. So slope =-2 Sufficient

(2) C = 4B Ax+By=C..........Ax+By=4B......y=-(A/B)X+4 So slope is -(A/B)....we don't know values of A and B.. Insufficient

If line k in the xy-coordinate plane has the equation Ax + By = C, wha
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23 Jul 2018, 08:37

Bunuel wrote:

If line k in the xy-coordinate plane has the equation Ax + By = C, what is the slope of line k ?

(1) A = 2B

(2) C = 4B

Given equation of line: Ax+By = C. We can simplify this equation further, as we know that the line of equation is in the form : y = mx + c

Dividing the giving equation with coefficient of y to get the standard form: (A/B)x + y = C/B or: y = -(A/B)x + C/B

In order to get the slope (m), we need the values of A/B.

(A) is sufficient to provide the slope of the line. Given A = 2B Hence, m = -(2B/B) = -2 SUFFICIENT

(B) By looking this option, it's not giving the relation between A and B. Also, after putting the value of C in equation, we will get the values in the form of A and B. Hence, NOT SUFFICIENT

Re: If line k in the xy-coordinate plane has the equation Ax + By = C, wha
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15 Nov 2018, 07:23

Top Contributor

Bunuel wrote:

If line k in the xy-coordinate plane has the equation Ax + By = C, what is the slope of line k ?

(1) A = 2B

(2) C = 4B

Given: Line k has the equation Ax + By = C

Target question:What is the slope of line k ? This is a good candidate for rephrasing the target question. Let's take the given equation Ax + By = C and rewrite it in slope y-intercept form, y = mx + b, where m = slope and b = y-intercept

GIVEN: Ax + By = C Subtract Ax from both sides to get: By = -Ax + C Divide both sides by B to get: y = -Ax/B + C/B Rewrite to get: y = (-A/B)x + C/B With the line's equation written in this form, we can see that line k has slope -A/B and y-intercept C/B So, we can REPHRASE our target question.... REPHRASED target question:What is the value of -A/B ?

Aside: Below is a video with tips on rephrasing the target question

Statement 1: A = 2B Divide both sides by B to get: A/B = 2 This means -A/B = -2 So, the answer to the REPHRASED target question is -A/B = -2 Since we can answer the REPHRASED target question with certainty, statement 1 is SUFFICIENT

Statement 2: C = 4B Since we have no information about A, there's no way to determine the value of -A/B Since we cannot answer the REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Answer: A

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Re: If line k in the xy-coordinate plane has the equation Ax + By = C, wha &nbs
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