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Answer:
3x -y -30 = 0
Step-by-step explanation:
The reference line for the intercept can be written in standard form as ...
2x +5y = 20
Setting y=0 and solving for x, we find the x-intercept to be ...
2x = 20
x = 20/2 = 10
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The line perpendicular to the first reference line can use the same x- and y-coordinates, but swapped, with one of them negated. If the line is right-shifted from the origin to the x-intercept point, its equation will be ...
3(x -10) -y = 0
In general form, this is ...
3x -y -30 = 0
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<em>Additional comments</em>
Perpendicular lines have slopes that are opposite reciprocals of each other. The slope of a line in general form is ...
m = -(coefficient of x)/(coefficient of y)
The opposite reciprocal of this can be had by swapping the coefficients and negating one of them.
In general form, we like to have the first coefficient positive, so we choose to negate the (new) y-coefficient in this problem.
The general form equation ax+by=0 would define a line through the origin. Using the usual methods for translating functions, we can make the line go through point (h, k) by writing the equation as a(x-h)+b(y-k) = 0. This is the method we used to make the line have the desired x-intercept.
