its not a funkshun...yu dont hav x on rite side
y=15*root(18) -1+3
so y=2+15*root(18)...18 is 9*2 & 9=3*3, so get
root(18)=3*root(2), so yu hav y=2+45*root(2)
root(2)=1.4142135623730950488016887242096980785...
tu yuze kalkulater, kut that down & yu hav 45*1.414213562
=63.63961031