Выражение: 1) 4(3a+1.+2a)-3(a-1/2) 2) -1.5(6-x)-2(-x-3)+0.9(5x-1) 3) 0.8(2y-3)+5(1.6-0.5y)-2(0.8y-1.7) 4) 5/6(1/5n+6)-2/3(9-1/2n)+5/8(4/5n-8) решите !

1. 12a + 6.4 - 5 + 2a - 3a + 2.5 = 11a + 3.9
2. -9 + 1.5x + 2x + 6 + 4.5x - 0.9 = 8x - 3.9
3. 1.6y - 2.4 + 8 - 2.5y - 1.6y + 3.4 = 9 - 2.5y
4. 1/6n + 5 - 6 + 1/3n + 1/2n - 5 = n - 6