Решите уравнения : а) 5x/2*6/x^2 б) (x-1)*2x+1/3x-3 в) 3x+6x/x-3*4x-12/x^2-4

А) 5x/2 * 6/x^2= 30x/2x^2=30x/2x(1x)=15x/x
b) 2x^2-2x+1/3-3=6x^2-6x/3+1/3-9/3=6x^2-6x+1-9/3=6x^2-6x-8/3
c) 3x^2+6x/x-3*4x-12/x^2-4  = 3x^3-12x^2+6x^2-24x-12x-12/x^2-4=3x^3-18x^2-36x-12/x^2-4=x(3x^2-18x-36-12)/x(1-4)=3x^2-18x-48/-3=3x^2-18x-16