SOLUTION: solve : log of x^2+x+4 to the base of 5 equals 2

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Question 797221: solve : log of x^2+x+4 to the base of 5 equals 2

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
solve : log of x^2+x+4 to the base of 5 equals 2
log%285%2C%28x%5E2%2Bx%2B4%29%29=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+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a=1, b=1, c=-21
ans:
x≈-5.11
or
x≈4.11