SOLUTION: Find the constant s so that the lines (2s+4)x +5y=-7 (s+4)x +3y =s are parallel. Thank you.

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Question 1011817: Find the constant s so that the lines (2s+4)x +5y=-7 (s+4)x +3y =s are parallel. Thank you.
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
(2s+4)x +5y=-7 (s+4)x +3y =s

We get both equations in slope-intercept form y = mx+b

We do that by solving the equation for y:

The first one in slope-intercept form is

y+=+expr%28-2%2F5%29%28s%2B2%29x-14%2F5

The second one in slope-intercept form is

y+=+expr%28-1%2F3%29%28s%2B4%29x%2Bexpr%281%2F3%29s

Compare both to y = mx + b

and their slopes are the coefficients of x.

So we set the two slopes equal to each other:

expr%28-2%2F5%29%28s%2B2%29%22%22=%22%22expr%28-1%2F3%29%28s%2B4%29

Solve that for s. Begin by clearing of fractions
by multiplying both sides by LCD = 15.

The answer is a positive whole number.

Edwin