1) 5t(t-5)+2=2+5t 2)1-6(x2-x-1)=7 3)u-2(u2+u-1)=2 4)5x2-2x(x-3)=0

1) 5t (t - 5) + 2 = 2 + 5t.

Раскроем скобки.

5t * t - 5 * 5t + 2 = 2 + 5t.

5t - 25t + 2 - 2 - 5t = 0.

5t - t (25 + 5) = 0.

5t - 30t = 0.

t (5t - 30) = 0.

По правилам t = 0, и 5t - 30 = 0.

5t = 30.

t = 30/5 = 6.

Ответ: t = 0, t = 6.

2) 1 - 6 (x - x - 1) = 7.

1 - 6 * x - 6 * (- x) - 6 * (- 1) = 7.

1 - 6x + 6x + 6 = 7.

- 6x + 6x + 7 - 7 = 0.

- 6x + 6x = 0.

x (- 6x + 6) = 0.

x = 0, и - 6x + 6 = 0.

- 6x = - 6.

x = 6/6 = 1.

Ответ: x = 0, x = 1.

3) u - 2 (u + u - 1) = 2.

Раскроем скобки.

u - 2 * u - 2 * u + 2 * 1 = 2.

u - 2u - 2u + 2 - 2 = 0.

- 2u + u (1 - 2) + 0 = 0.

- 2u - u = 0.

- u (2u - 1) = 0.

По правилам корнями уравнения являются корни уравнений:

- u = 0, u = 0.

2u - 1 = 0, 2u = 1, u = 1/2.

Ответ: u = 0, u = 1/2.

4) 5x - 2x (x - 3) = 0.

Раскроем скобки.

5x - 2x * x + 2x * 3 = 0.

5x - 2x + 6x = 0.

x (5 - 2) + 6x = 0.

3x + 6x = 0.

x (3x + 6) = 0.

x = 0, и 3x + 6 = 0.

3x = - 6.

x = - 6/3 = - 2.

Ответ: x = 0, x = - 2.