Question

2³¹ + 2³⁰ + 2²⁹ = x · 2²⁸
x=?

Answer 1

$2^{31}+ 2^{30}+2^{29}=x*2^{28} \\\\ 2^{28}(2^3+2^2+2)=x*2^{28} \\\\ 2^3+2^2+2=x \\\\ x=8+4+2 \\\\ \boxed{x=14}$

Answer 2

$2^{31}+2^{30}+2^{29}=\\ 2^{28}(2^3+2^2+2)=\\ 2^{28}(8+4+2)=\\ 2^{28}\cdot14\\\\ x=14$