Given

we have

Squaring both sides, we have

And finally

Note that, when we square both sides, we have to assume that

because we're assuming that this fraction equals a square root, which is positive.
So, if that fraction is positive you'll actually have roots: choose

and you'll have

Which is a valid solution. If, instead, the fraction is negative, you'll have extraneous roots: choose

and you'll have

Squaring both sides (and here's the mistake!!) you'd have

which is not a solution for the equation, if we plug it in we have

Which is clearly false
 
        
             
        
        
        
Answer: 30 buttons
Step-by-step explanation:
If there were 8 kids, and 7 more joined, then there were 15 kids making snowmen (8+7 = 15).  Each child used 2 buttons for the eyes, so 30 buttons were used (15 x2 = 30).  This is assuming no other buttons were used on the snowmen for anything else
 
        
             
        
        
        
Answer:
7r^2-64r+64
49r-64r+64
-15r+64
Step-by-step explanation: