Question 797221
solve : log of x^2+x+4 to the base of 5 equals 2
{{{log(5,(x^2+x+4))=2}}}
convert to exponential form:(base(5) raised to log of number(2)=number(x^2+x+4)
5^2=(x^2+x+4)
(x^2+x+4)=25
x^2+x-21=0
solve for x by quadratic formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
a=1, b=1, c=-21
ans:
x≈-5.11
or
x≈4.11