Triangle has a total of 180 degrees
add up all angles
A+B+C = 3x+5+4x-2+2x+6=180
9x=171
x=19
Plug x values into the A , B and C expressions and you get your answers
The answer is x=7 hope this helps:)
X= -2
put x+3=-2x-3
+3. +3
x+6=-2x
-x. -x
6= -3x
/3. /3
x=-2
<h3>Substitute and Check:</h3>

<h3>We can stop here and conclude that ( 1 , 3 ) is not a solution to this system, since it does not even satisfy the first equation, but check for the other one just in case:</h3>

1980mg(g/1000mg)=1.98g
2g-1.98g=0.02g or 20mg is the difference between the two weights.