In the xy plane, if line k has negative slope and passes through the point (-5, r), is the x intercept of line k positive?
1) The slope of line k is -5
2) r>0
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what is the answer?
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Many slope problems are best solved by DRAWING.In the xy-plane, if line k has negative slope and passes through the point (-5, r), is the x-intercept of line k positive?
1) slope of line k is -5
2) r > 0
oa-E
Statement 1: Slope = -5
Statement 2: When x = -5, r > 0
Both statements are satisfied by the following cases:
Case 1:
Here, the x-intercept is negative.
Case 2:
Here, the x-intercept is positive.
Thus, the two statements combined are INSUFFICIENT.
The correct answer is E.
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swathi8388
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My guess is that the answer is E.
We know that slope is negetive and passes through (-5,r) the question is to find the x intercept.
let k's equation be y=mx+c , x intercept is the value when y=0 , so plugging in y=0 in the equation we get 0=mx+c or x=-c/m , and the quesiton is wheter -c/m is positive or not.
1. says that m is -5 so we kno that x= -c/-5 = c/5 , but since we do not know whether c is -ve or +ve this option doesnt help us.
2. r>0 which means the line passes throuh (-5,r) where r is a positive number
hence plugging in the values in k's equation x=-5 and y=r we get r = -5m+c
since we dont know the numerical value of r we dont know whether the value of c is +ve or -ve which means we cant predict the value of -c/m
We know that slope is negetive and passes through (-5,r) the question is to find the x intercept.
let k's equation be y=mx+c , x intercept is the value when y=0 , so plugging in y=0 in the equation we get 0=mx+c or x=-c/m , and the quesiton is wheter -c/m is positive or not.
1. says that m is -5 so we kno that x= -c/-5 = c/5 , but since we do not know whether c is -ve or +ve this option doesnt help us.
2. r>0 which means the line passes throuh (-5,r) where r is a positive number
hence plugging in the values in k's equation x=-5 and y=r we get r = -5m+c
since we dont know the numerical value of r we dont know whether the value of c is +ve or -ve which means we cant predict the value of -c/m
