12.8. Решите уравнение: 1) х2 – х = 0;
2) p2 + 15p = 0;
3) 5х2 – 30x = 0;
4) 14х2 + 18x = 0.

1) х2=-х

2)р2=-15р

3)5х2=30х

4)14х2=-18х

1) x1 = 0 , x2 = 1

2) p1 = 0 , p = -15

3) x1 = 0 , x2 = 6

4) x1 = 0 , x2 = -9/7

Пошаговое объяснение:

1) х^2 - х = 0

x(x - 1) = 0

x = 0 , x - 1 = 0

          x = 1

2) p^2 + 15p = 0

p(p + 15) = 0

p = 0 , p + 15 = 0

            p = -15

3) 5х^2 - 30x = 0

5x(x - 6) = 0

5x = 0 , x - 6 = 0

x = 0 ,   x = 6

4) 14х^2 + 18x = 0

2x(7x + 9) = 0

2x = 0 , 7x + 9 = 0

x = 0 ,   7x = -9

            x = -9/7