(x+(x+2)+(x+4)+(x+6))=4x+12=212
x+x+x+x(2+4+6)=4x+12=212
4x (2+4+6)=4x+12=212
4x(6+6)=4x+12=212
12+4x=4x+12=212
-12 -12 -12
4x=4x=200
/4 /4 /4
x=x=50
x=50
