2,4×2/5-23%= 4+42%:0,8 =

2,4 = 12/5
23% = 23/100
12/5 x 2/5 - 23/100 = 24/25 - 23/100 = 96/100 - 23/100 = 73/100

4 = 400/100
42% = 42/100
0,8 = 4/5 = 80/100
400/100 + 42/100 ÷ 80/100 = 400/100 + 21/40 = 181/40

ps: maap yaa kalo salahh