Question 253286

You should be making two equations with two unknowns.
You substituted 3w for w instead of 3w for e
Don't use x for multiplication sign
Use the asterisk above the number 8
Also we usually put numbers before letters
3w not w3
w3 can be confused for w^3
Mathematics is a language and has rules just like English and Spanish
and it has its own vocabulary and word order.

e=3w
(e+4)=2(w+4)
substitute 3w for e
3w+4=2w+8
subtract 2w from both sides
subtract 4 from both sides

w=4
e=3*w=12
check

12+4=2(4+4)
16=2*8
16=16