On comparing the ratios a1/a2 = b1/b2 = c1/c2 and without drawing them, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincide: ​(i) 5x−4y+8=0, 7x+6y−9=0 ​(ii) 9x+3y+12=0, 18x+6y+24=0 (iii) 6x-3y+10=0, 2x-y+9=0