75:a=3 6x+x=42 5x+5=20
2)6x+x=42 3)5x+5=20 75:а=3 7x=42 5x=20-5 а=3:75 x=42/7 5x=15 а=0,04 x=6 x=15/5 x=3
75 : a = 3 a = 75:3 a = 25 -------------- 6x + x = 42 7x = 42 x = 42 : 7 x = 6 ------------ 5x + 5 = 20 5x = 20 - 5 5x = 15 x = 15 : 5 x = 3