Question

8^x=-,0.25
(7/3)^4x-x^2+1=81/2401

Answer 1

$(frac{7}{3}) ^{4x- x^{2} +1} = frac{81}{2401}$
$(frac{7}{3}) ^{4x- x^{2} +1} = ( frac{7}{3})^{-4}$
$4x- x^{2} +1=-4$
$- x^{2} +4x+5=0$
$x^{2} -4x-5=0$
$x_{1} =-1, x_{2}=5$