Parallel & Perpendicular Lines Quick Check

4 of 54 of 5 Items
Question
Which line is perpendicular to the line y=−74x
and goes through the point (−7,5)
?(1 point)
Responses

y=4/7x+9
y equals Start Fraction 4 over 7 End Fraction x plus 9

y=−4/7x+1
y equals negative Start Fraction 4 over 7 End Fraction x plus 1

y=−7/4x+5
y equals negative Start Fraction 7 over 4 End Fraction x plus 5

y=4/7x+5

1 answer

To determine which line is perpendicular to the line \( y = -\frac{7}{4}x \) and goes through the point \((-7, 5)\), we first need to find the slope of the given line and then identify the slope of the line that would be perpendicular to it.

  1. Identify the slope of the given line: The slope of the line \( y = -\frac{7}{4}x \) is \( -\frac{7}{4} \).

  2. Determine the slope of the perpendicular line: The slope of a line perpendicular to another line is the negative reciprocal of the original slope. The negative reciprocal of \(-\frac{7}{4}\) is: \[ \frac{4}{7} \]

  3. Use the point-slope form to find the equation of the perpendicular line: Using the point \((-7, 5)\) and the slope \(\frac{4}{7}\), we can use the point-slope form: \[ y - y_1 = m(x - x_1) \] Substitute \( (x_1, y_1) = (-7, 5) \) and \( m = \frac{4}{7} \): \[ y - 5 = \frac{4}{7}(x + 7) \]

    To write it in slope-intercept form (y = mx + b), we can expand and simplify: \[ y - 5 = \frac{4}{7}x + 4 \] \[ y = \frac{4}{7}x + 9 \]

Now we look at the provided responses:

  1. \( y = \frac{4}{7}x + 9 \)
  2. \( y = -\frac{4}{7}x + 1 \)
  3. \( y = -\frac{7}{4}x + 5 \)
  4. \( y = \frac{4}{7}x + 5 \)

The first option, \( y = \frac{4}{7}x + 9 \), is the correct line that is perpendicular to \( y = -\frac{7}{4}x \) and passes through the point \((-7, 5)\).

Thus, the answer is: y = \frac{4}{7}x + 9.