Question

Nr natural x care verifică 4^x+2 - 5•4^x =44 este: a) 4 b) 1 c) 0 d) 2

Answer 1

$\it 4^{x+2}-5\cdot4^x=44 \Rightarrow 4^x(16-5)=44 \Rightarrow4^x\cdot11=44|_{:11}\Rightarrow4^x=4\Rightarrow x=1$