4^(x+2)=[4^(4x-10)]/[3^(8x-20)]
3^(8x-20)=4^(4x-10)/4^(x+2)
3^(8x-20)=4^(3x-12)
3^(8x-20)=2^(6x-24)
прологарифмируем по основанию 2
(8x-20)*log(2)3=(6x-24)log(2)2
(8x-20)*log(2)3=(6x-24)
8x*log(2)3-6x=-24+20*log(2)3
2x*(4log(2)3 -3)=2(10log(2)3 -12)
x=(10log(2)3 -12)/(4log(2)3 -3)