On comparing the ratios a1a2, b1b2 and c1c2, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincident : (i) 5x−4y+8=0 7x+6y−9=0 (ii)9x+3y+12=0 18x+6y+24=0
Open in App
Solution
(i) 5x−4y+8=0 7x+6y−9=0
Now, a1a2=57 and b1b2=−46=−23
Since, a1a2≠b1b2, above equations will have unique solution.
∴ the above lines will intersect at a point.
(ii) 9x+3y+12=0
18x+6y+24=0
Now, a1a2=918=12, b1b2=36=12 and c1c2=1224=12
Since, a1a2=b1b2=c1c2, above lines will be co-incident.