Wht is the venn diagram of an empty set like?

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years