Based on the given condition Diego utilized, it can be said that he used multiplication property when he multiplied both sides of the equation by 6 and then substitution property when he substituted 6 to the original equation.
(c) Multiplication property of equality and substitution property of equality
(9x + 5) - (4x+3) = 0
9x - 4x + 5 - 3 = 0
5x + 2 = 0
5x = -2
5x/5 = -2/5
x= -2/5
