Question

need help solving 3 equations here.

Answer 1

well it seems you haven't included the equation in the information.

The way the question reads... the equation is given to you.

Answer 2

I derived the expression for the temperature obtained by mixing two masses of water at two different temperatures: \[T=\frac{ m _{1}T _{1} +m _{2}T _{2}}{ m _{1} +m _{2}}\] where m1 and m2 are the masses of the two volumesof water and T1 and T2 are their respective temperatures. I hope this helps.