Which of the following expressions could be used to find the sale price of an item that costs d dollars if it is on sale for 30%
1 answer:
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a) The equation of line k is:
b) The equation of line j is:
The equation of a line, in <u>slope-intercept formula</u>, is given by:
In which:
- m is the slope, which is the rate of change.
- b is the y-intercept, which is the value of y when x = 0.
Item a:
- Line k intersects line m with an angle of 109º, thus:
In which and
are the slopes of <u>k and m.</u>
- Line k goes through points (-3,-1) and (5,2), thus, it's slope is:
- The tangent of 109 degrees is
- Thus, the slope of line m is found solving the following equation:
Thus:
It goes through point (-2,6), that is, when , and this is used to find b.
Thus. the equation of line k, in slope-intercept formula, is:
Item b:
- Lines j and k intersect at an angle of 90º, thus they are perpendicular, which means that the multiplication of their slopes is -1.
Thus, the slope of line j is:
Then
Also goes through point (-2,6), thus:
The equation of line j is:
A similar problem is given at brainly.com/question/16302622