(7一2.4)x+5=7.8 4.6x+5=7.8 4.6x=7.8-5=2.8x=28/46=14/23
4.6x+5=7 4.6x=2 x=10/23
4.6x=2.8x=14╱23
4.6x=2.8; x=14/23