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Write an equation of a line passing through the point (-4, -11) and perpendicular to the line 4x + 5y = -45.

A) y = (5/4)x - 16
B) y = (5/4)x - 6
C) y = (4/5)x + 1
D) y = (4/5)x + 5
E) y = (-4/5)x - 8

1 Answer

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Final answer:

The equation of the line passing through the point (-4, -11) and perpendicular to the given line is y = (5/4)x - 6. To find this, we first determined the slope of the given line, which is -4/5, and then found the negative reciprocal for the perpendicular line, which is 5/4. Finally, we used point-slope form to derive the equation of the new line, arriving at option B.

Step-by-step explanation:

To write an equation of a line passing through the point (-4, -11) and perpendicular to the line 4x + 5y = -45, we must first find the slope of the given line and then determine the slope of the line perpendicular to it.

The given line 4x + 5y = -45 can be written in slope-intercept form: y = mx + b, where m is the slope. We rearrange the given equation to find the slope of the given line:

  • 5y = -4x - 45
  • y = (-4/5)x - 9

The slope of the given line is -4/5, so the slope of a line perpendicular to it would be the negative reciprocal, which is 5/4.

Now, using the slope 5/4 and the point (-4, -11), we use the point-slope form of a line equation, which is y - y1 = m(x - x1), to find the equation of the new line:

  • y - (-11) = (5/4)(x - (-4))
  • y + 11 = (5/4)x + 5
  • y = (5/4)x + 5 - 11
  • y = (5/4)x - 6

Therefore, the equation of the line passing through the point (-4, -11) and perpendicular to the line 4x + 5y = -45 is y = (5/4)x - 6, which corresponds to option B.