GreenlightTestPrep wrote:
In the x-y coordinate plane, (the slope of line k)(the y-intercept of line k) > 0. Which of the following MUST be true?
Select all that apply.
A) Line k has a negative x-intercept
B) (slope of line k) - (x-intercept of line k) > 0
C) |slope of line k| > 0
Answer:
(the slope of line k)(the y-intercept of line k) > 0
So two cases:-
Case I.. both slope and y intercept are positive
Case II.. both slope and y intercept are negative
When we talk of slope there are 3 things...
1) slope
2) y-intercept
3) x-intercept
So let us see what happens to x intercept in above cases
Case I...
Now slope = \(\frac{(y-0)}{(0-x)}\)
Thus 0-x>0.....X<0, so a negative intercept..
Case II...
slope = \(\frac{(y-0)}{(0-x)}\)
But slope and y intercept are negative, so -=-/?
So 0-x=-/- or 0-x>0....X<0
Again negative x-intercept..
Also look at the sketch, in each case x-intercept is negative
so A is correct..
B means (slope of line k) - (x-intercept of line k) > 0 ...
Both have opposite sign..
So (+)-(-)=+>0
(-)-(+)=-<0
Need not be true
C) |slope of line k| > 0
Now slope of line will not be 0 as slope*y-intercept>0
So C is also true
A and C
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