Answer:
• let's first get the percentage decrease:

• then multiply the percentage decrease with the mass given:

I don't really see how this pertains to Mathematics...
Let us pretend x is the number.
The equation will be 13-6x=11+4x.
Solve.......
X=2/10
Answer:
Step-by-step explanation:
All methods are supposed to be correct in most if not all situations and it should not matter if you use a different method given the options