Y^y=16

pls help

Assuming Y is the same as y

there is no easy way to do this.
if y = 2 ---- 2^2 = 4
if y = 3 ---- 3^3 = 27
if y = 2.7 --- 2.7^2.7 = appr 14.6
if y = 2.8 ---- 2.8^2.8 = appr 17.9
so you know 2.7 < y < 2.8
you can keep "sandwiching" the value of y this way using your calculator

btw. Wolfram says y = appr 2.74537