Question 214155
a.
Let x=number of green eyed dolls
Ane let y=number of blue-eyed dolls

Now we are told the following:
x+y=52----------------------------------eq1
and
y=x+16------------------------------------eq2

b.  
substitute y=x+16 from eq2 into eq1:
x+x+16=52 subtract 16 from each side
x+x+16-16=52-16  collect like terms
2x=36  divide each side by 2
x=18--------------------------number of green-eyed dolls
substitute x=18 into eq2
y=18+16=34----------------------number of blue-eyed dolls

CK
18+34=52
52=52
and
18+16=34
34=34

THIS PROBLEM CAN ALSO BE SOLVED USING ONE EQUATION AND ONE UNKNOWN:

Let x=number of green-eyed dolls
Then 52-x=number of blue-eyed dolls
Now we are told that:
x+16=52-x add x to and subtract 16 from each side 
x+x+16-16=52-16-x+x  collect like terms
2x=36-------------------same as before

Hope this helps---ptaylor