Answer:
Option C is correct.
Step-by-step explanation:
Diego solved an equation by multiplying both sides of the equation by 6.
Then he checked that 6 is the correct solution by substituting it back into the equation.
The properties that Diego used are :
C: multiplication property of equality and substitution property of equality
The multiplication property of equality states that if we multiply both sides of an equation by the same number, the sides remain equal.
And the substitution property of equality states that if x = y, then x can be substituted in for y in any equation. Similarly, y can be substituted for x in any equation.
Therefore, Diego used both these properties. (Option c)
