SOLUTION: find the equation of a line that is perpendicular to the graph of 3x-4y=-21, and goes through the point (-1,0). Write the answer in slope-intercept and standard form.

Algebra ->  Graphs -> SOLUTION: find the equation of a line that is perpendicular to the graph of 3x-4y=-21, and goes through the point (-1,0). Write the answer in slope-intercept and standard form.      Log On


   



Question 199715: find the equation of a line that is perpendicular to the graph of 3x-4y=-21, and goes through the point (-1,0). Write the answer in slope-intercept and standard form.
Answer by J2R2R(94) About Me  (Show Source):
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Find the equation of a line that is perpendicular to the graph of 3x - 4y = - 21, and goes through the point (-1, 0). Write the answer in slope-intercept and standard form.

3x - 4y = - 21

Gives 4y = 3x + 21 or y = 3x/4 + 21/4 giving a gradient of 3/4

The product of the gradients of perpendicular lines equals - 1, so the gradient of the perpendicular line is - 4/3

As it passes through (-1, 0) we have 0 = - 4(-1)/3 + c; 0 = 4/3 + c; c = - 4/3;

y = - 4x/3 - 4/3 or 4x + 3y = - 4