$3\left( x-3 \right)-2\left( 4x-3 \right)-6=-\left( 5x-12 \right)$
Distribute $3$ through the parentheses$3x-9-2\left( 4x-3 \right)-6=-\left( 5x-12 \right)$
Distribute $-2$ through the parentheses$3x-9-8x+6-6=-\left( 5x-12 \right)$
When there is a $-$ in front of an expression in parentheses, change the sign of each term of the expression and remove the parentheses$3x-9-8x+6-6=-5x+12$
Since two opposites add up to $0$, remove them from the expression$3x-9-8x=-5x+12$
Collect like terms$-5x-9=-5x+12$
Cancel equal terms on both sides of the equation$-9=12$
The statement is false for any value of $x$$∅$