Assuming that x is damaged, then
1.5( 100-x)- 15x = 84
The solution is x=4.
Four vases were damaged.
For supplementary questions:
1.5 *( 100-x)- 15 * x = 84
Is that clear? Subtract the compensation for the damaged vase (this answer is purely plagiarism, and it is normal if there is any similarity. )