Can I get this answers please ​

Is a currency whose value is tied to another currency, meaning that the exchange is fixed

In the diagram, the measure of angle 9 is 85° which angle must also measure 85°?

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36