What are the equivalent ratios of 5: 6

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

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

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.