Answer:
First equation is equivalent to 54x-12 and 6*9x - 6*2
Second equation is equivalent to 10y + 11y and 21y
Explanation:
The first equation, 6(9x-2) is considering distribution, if you were to multiply all terms in the parentheses by 6, the base, you would get 54x-12. Since the fourth equation is the same thing, just less simplified, both the second and fourth equations are equivalent here.
The second equation, 10y + 6y + 5y, is combining like terms. Technically, all this is saying is 21y since you can add like terms together. Therefore the first and third equations are correct. The fourth is not because 21y is 21 times the value of y, whereas 21 + y is just 21 by itself plus y.