Question

(1/20)^2x-6=400 ..................

Answer 1

20^(6-2x)=20²
6-2x=2
2x=6-2=4
x=4:2=2

Answer 2

$( \frac{1}{20}) ^{2x-6} =20^2$
$20^{6-2x} =20^2$
$6-2x=2$
$2x=4$
$x=2$
Ответ: 2