Question

Write the standard form equation (Ax + By + C =0) for a line that is perpendicular to

y= 2x + 7 and has the same y-intercept as the line y=5x - 5.

Put only the coefficients for A, B and C

Answer 1

A = 1

B = 2

C = 10

Explanation:

slope intercept form is

y = mx + b

m is the slope

b is the y-intercept

The slopes of parallel lines are negative reciprocals

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y = 2x + 7

slope = 2

slope of perpendicular line is the negative reciprocal of 2

slope = -1/2

y = 5x - 5

y-intercept is -5

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slope intercept form of perpendicular line

using slope = -1/2 and y-intercept = -5

y = -(1/2)x - 5

Change to standard form:

multiply both sides by 2

2y = -x - 10

Add x + 10 to both sides

x + 2y + 10 = 0

Therefor

A = 1

B = 2

C = 10