The symbol ":" and "::" represents a proportion.
6:x::3:(1+2) means "6 is to x" as "3 is to (1+2)"
In equation form:
x6=1+23
Cross-multiplying:
6×(1+2)=x×3
6+6⋅2=x3
Simplifying 6⋅2:
6⋅2=12
12=4×3=23
Therefore:
6+23=x3
Rewriting 6:
6=2×3=2⋅3
Substituting:
2⋅3+23=x3
Factoring out 3:
3(2+2)=x3
Dividing both sides by 3:
x=2+2
Therefore, x=2+2.