Solve each equation for 'x' ....then switch the 'x' and 'y'....
I'll do the third one....you try the other two
y = sqrt(5x-6) square both sides
y^2 = 5x-6 add 6 to both sides
y^2 + 6 = 5x divide both sides by 5
(y^2+6)/5 = x now swithch the 'x's and 'y's
y = (x^2+6) / 5 done!