Answer :

Isolate for x

First expand the bracket to

12x^2 - 15x = 12x - 5
Move everything to one side

12x^2 - 27x + 5

Use quadratic formula and sub in values

X = 2.046989
X = 0.203610
phantomore
Original :
3x(4x)+3x(5)=12x-5

Distributive Property :

3x(4x)+3x(5)=12x-5
12x+15x=12x-5

Combine like terms :

27x=12x-5 

Isolate the terms :

27x-12x=12x-12x-5
15x=-5

Simplify :

15x/15=-5/15
x=-1/3

Answer :

x=-1/3 or x=-0/333...