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Find the equation of a line perpendicular to 4x + 3y= -24that passes through the point (-8,3).

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Answer:

Equation (in slope-intercept form): y = 3/4x + 9

Equation (in standard form): -3x + 4y = 36

You can use either equation as both are correct with the only difference being the form.

Explanation:

Relationship between the slopes of perpendicular lines:

  • The slopes of perpendicular lines are negative reciprocals of each other.

We can represent this with the equation m2 = -1/m1, where:

  • m1 is the slope of the line we're given,
  • and m2 is the slope of the line we're trying to find.
  • 4x + 3y = -24 is in the standard form of a line, but we can can identify its slope by converting it slope-intercept form.

Converting 4x + 3y = -24 to slope-intercept form and identifying its slope (i.e., m1):

The general equation of the slope-intercept form is given by:
y = mx + b, where:

  • m is the slope,
  • and b is the y-intercept.

Thus, we can can convert 4x + 3y = -24 to slope-intercept form by isolating y:

(4x + 3y = -24) - 4x

(3y = -4x - 24) / 3

y = -4/3x - 8

Thus, the slope of 4x + 3y = -24 is -4/3.

Finding the slope of the other line (i.e., m2):

Now, we can find the slope of the other line by substituting -4/3 for m1 in the perpendicular slope equation:

m2 = -1 / (-4/3)

m2 = -1 * (-3/4)

m2 = 3/4

Thus, the slope of the other line is 3/4.

Finding the y-intercept of the other line and writing the equation of the line:

Now, we can find the y-intercept (b) of the other line by substituting (-8, 3) for (x, y) and 3/4 for m in the slope-intercept form:

3 = 3/4(-8) + b

3 = -24/4 + b

(3 = -6 + b) + 6

9 = b

Thus, the y-intercept of the other line is 9.

Therefore, y = 3/4x + 9 is the equation of a line perpendicular to 4x + 3y = -24 and passing through the point (-8, 3).

----------------------------------------------------------------------------------------------------------Converting y = 3/4x + 9 to standard form:

  • Since the other line is given in standard form, we can convert y = 3/4x + 9 to standard form for the sake of continuity.

First, let's clear the fraction by multiplying the entire equation by 4:

4(y = 3/4x + 9)

4y = 3x + 36

Now, we need to isolate 36 on the right-hand side:

(4y = 3x + 36) - 3x

-3x + 4y = 36

Thus, -3x + 4y = 36 is also the equation of a line perpendicular to 4x + 3y = -24 and passing through the point (-8, 3).

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