Решите уравнения

1. (√2-1) (x+1) = 0

2. 0.2 (x-5) + 0.8 (1-x) - 2.4 (2x+5) = 4

3. 2x (x-2) + 3x²-5 (x²+6x+1) = 12

4. 3 (x-12) - 4x·0.75=-36

1. (√2-1) (x+1) = 0

х+1=0

х=-1

2. 0.2 (x-5) + 0.8 (1-x) - 2.4 (2x+5) = 4

0,2 х-1+0,8-0,8 х-4,8 х-12=4

-5,4 х=4+1-0,8+12=16,2

х=16,2: (-5,4) = - 3

3. 2x (x-2) + 3x²-5 (x²+6x+1) = 12

2 х²-4 х+3 х²-5 х²-30 х-5=12

-34 х=17

х=-17/34=-0,5

4. 3 (x-12) - 4x·0.75=-36

3 х-36-3 х=-36

0 х=0

х∈ (-∞; ∞)