Решите уравнение (6x+5)^2-4x(3+9x)=49

Найдем х.

(6 * x + 5) - 4 * x * (3 + 9 * x) = 49; 

(6 * x) + 2 * (6 * x) * 5 + 5 - 4 * 3 * x - 4 * 9 * x * x = 49; 

36 * x + 10 * 6 * x + 25 - 12 * x - 36 * x = 49; 

36 * x + 60 * x + 25 - 12 * x - 36 * x = 49; 

(36 * x - 36 * x) + (60 * x - 12 * x) + 25 = 49; 

x * (36 - 36) + x * (60 - 12) + 25 = 49; 

x * 0 + x * 48 + 25 = 49; 

48 * x + 25 = 49; 

48 * x = 49 - 25; 

48 * x = 24; 

x = 24/48; 

x = 1/2; 

x = 0.5.