Question

com calculo
4²x-100=0

Answer 1

$4x^2-100=0\\ \\ 4x^2=100\\ \\ x^2=\frac{100}{4}\\ \\ x^2=25\\ \\ \boxed{x= \pm 5}$

Answer 2

4²x-100=0
16x-100=0
16x=100
x=100/16
x=6.25