Use the distributive property to create an equivalent expression to 54+18x

Ab+ac=a(b+c)
a is a common factor

factor to find common factor

54=2*3*3*3
18=2*3*3*x
gcf=2*3*3=18

18(3)+18(x)=18(3+x)

First, you find a common factor between the two numbers, which, in this case, would be 18. So, you divide everything by 18 and you put the 18 outside the parentheses.

That would be equal to
18(3+x)
The x is truly a 1x, but there is no need to include the 1.

Figure it out your self