Answer:
The mass of the metal is 12.6 kg
Explanation:
Let the mass of the metal be x
From the question
5/9 of the metal is 7kg
That's

Multiply through by 9
We have
5x = 7 × 9
5x = 63
Divide both sides by 5

We have the final answer as
x = 12.6 kg
The mass of the metal is 12.6 kg
Hope this helps you