Question

Помогите, пожалуйста!
$4^ x^{+2} - 4^x geq 240$

Answer 1

$4^{x+2}-4^x geq 240$
$4^2*4^x-4^x geq 240$
$16*4^x-1*4^x geq 240$
$15*4^x geq 240$
$4^x geq 240:15$
$4^x geq 16$
$4^x geq 4^2$
4>1
$x geq 2$
x є $[2;+infty)$