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Write an equation (a) in slope intercept form and (b) in standard form for the line passing through (2,7) and perpendicular to 3x + 5y = 1

User Rolle
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Answer:

Explanation:

Solve 3x + 5y = 1 for y to obtain the slope of the given line:

5y = -3x + 1, or y = (-3/5)x + 1.

Any line perpendicular to this one has the slope which is the negative reciprocal of (-3/5): That would be 5/3.

The desired line has slope 5/3 and passes through (2, 7);

Adapt y = mx + b by substituting the known values, to find b:

7 = (5/3)(2) + b. The LCD is 3, so multiply each term by 3 to eliminate the fractional coefficient:

21 = 10 + 3b, or 11 = 3b. Then b = 11/3, and the desired equation in slope intercept form is

y = (5/3)x + 11/3

To obtain the standard form, multiply all three terms by 3 again:

3y = 5x + 11, or

5x + 11 - 3y = 0, or

5x - 3y + 11 = 0

User Vonbrand
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