log(7/10)*(x2 + 2*x) >= log(7/10)*(x2 + 16)
(2*x + x2)*log(7/10) >= (x2 + 16)*log(7/10)
/ -16*log(10) + 16*log(7) \ And|x <= -----------------------, -oo < x| \ -2*log(10) + 2*log(7) /
(-oo < x)∧(x <= (-16*log(10) + 16*log(7))/(-2*log(10) + 2*log(7)))