The <span>isosceles triangle has two congruent sides
Their lengths are (</span> x + 3.8 ) and  <span>16
Equate them :
x+3.8=16
Solve for x:
3=16-3.8=12.2
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Answer:
2
Step-by-step explanation:
You would replace the x with -2x so you would end up with -2×-2 and that is 4 then minus 2 is 2. 
 
        
             
        
        
        
Answer:
you are dumbbbbbb
Step-by-step explanation:
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It's important that you share the complete question.  What is your goal here?  Double check to ensure that you have copied the entire problem correctly.
The general equation of a circle is x^2 + y^2 = r^2.  Here we know that the circle passes thru two points:  (-3,2) and (1,5).  Given that a third point on the circle is (-7, ? ), find the y-coordinate of this third point.
Subst. the known values (of the first point) into this equation:  (-3)^2 + (2)^2 = r^2.  Then 9 + 4 = 13 = r^2.
Let's check this.  Assuming that the equation of this specific circle is 
x^2 + y^2 = r^2 = 13, the point (1,5) must satisfy it.
(1)^2 + (5)^2 = 13 is not true, unfortunately.
(1)^2 + (5)^2 = 1 + 25 = 26 (very different from 13).
Check the original problem.  If it's different from that which you have shared, share the correct version and come back here for further help.
        
             
        
        
        
1 and 2 are vertical 
3 and 4 are adjacent