Question

помогите решить уравнения по алгебре)
√x-4=5;
√1-3x=2;
√25-x*2=4;
√x*2-256=12;
√x+7=7;
√6x-1=1;
√x+2-81=12;
√625-x*2=15;

Answer 1

x - 4 = 5²
x - 4 = 25
x = 25 + 4
x = 29

1 - 3x = 2²
1 - 3x = 4
- 3x = 4 - 1
- 3x = 3
3x = - 3
x = - 1

25 - x² = 4²
- x² - 16 + 25 = 0
- x² + 9 = 0
x² - 9 = 0
D = b² - 4ac = 0² - 4 × 1  × ( - 9) = 36 = 6²
x₁ = 0 + 6/2 = 3
x₂ = 0 - 6/2 = - 3

x² - 256 = 12²
x² - 256 - 144 = 0
x² - 400 = 0
D = b² - 4ac = 0² - 4 × 1 ( - 400) = 1600 = 40²
x₁ = 0 + 40 / 2 = 20
x₂ = 0 - 40 / 2 = - 20

x + 7 = 7²
x + 7 = 49
x = 49 - 7
x = 42

6x - 1 = 1²
6x = 1 + 1
6x = 2
x = 2/6
x = 1/3

x + 2 - 81 = 12²
x - 79 = 144
x = 144 + 79
x = 223

625 - x² = 15²
- x² + 625 = 225
- x² = 225 - 625
- x² = - 400
x² = 400
x - 400 = 0
D = b² - 4ac = 0² - 4 × 1 × ( - 400) = 1600 = 40²
x₁ = 0 + 40 / 2 = 20
x₂ = 0 - 40 / 2 = - 20