#1) is 9*6+9*x equivalent to 9(6+x)

#2) is x+(8*9) equivalent to(x+8)*9

9(6+x)

by the distributive property,
distributing the 9 to each term in the brackets,
we get,

9*6 + 9*x

So yes, #1 is true.

(x+8)9

again by the distributive property,
giving the 9 to each term in the brackets,

x*9 + 8*9

which is NOT the same as

x + (8*9)

so #2 is false.

Hope that helps.

The difference is 5,100m?