Решить уравнения

А) 3x2-10x+3=0.

Б) 71x2+144x+4=0.

В) 9x2-30x+25=0.

7 наверно но перерешите

3x²-10x+3 = 0;

D = 100 - 4 * 3 * 3 = 100 - 36 = 64

x1 = (10 - 8) / 6 = 2/6 = 1/3

x2 = (10+8) / 6 = 3;

71x² + 144x + 4 = 0;

D = 20736 - 4 * 71 * 4 = 20736 - 1136 = 19600

x1 = (-144-140) / 142 = - 2;

x2 = (-144+140) / 142 = - 4/142

9x²-30x+25 = 0;

D = 900 - 4 * 9 * 25 = 0;

x1 = 30/18 = 5/3