Question

q<br />$find \: the \: value \: of \: r \: for \: which \: the \: pair \: of \: q \\ equations \: 2x + ry + 3 = 0 \: 4x + 6y - 5 = 0 \: represent \: parallel \: lines$<br />​

Answer 1

Solution:

Given system of equations:

2x+ry+3 = 0,

4x+6y-5 = 0 compare these

with a1x+b1y+c1 = 0 and

a2x+b2y+c2 = 0, we get

a1= 2, b1=r,c1=3;

a2=4, b2=6, c2 = -5

Now ,

a1/a2 = b1/b2 = c1/c2

/* Given lines are parallel */

=> 2/4 = r/6

=> (2×6)/4 = r

=> 3 = r

Therefore,

r = 3

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