Question

detwrmina nr nat x care verifica egalitatile:12•4^x-5•4^x=7•2^12??? va rog

Answer 1

12 x 4ˣ - 5 x 4ˣ = 7 x 2¹²

4ˣ x ( 12 - 5 ) = 7 x 2¹²

4ˣ x 7 = 7x 2¹²  l   : 7

( 2² )ˣ = 2¹² ⇒   2 x = 12 ⇒  x = 12 : 2 ⇒   x = 6