# Algebra

Solve x^(1/2)-(81x)^(1/4)-4=0

x^(1/2)-3(x)^(1/4)-4=0

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1. If you let u = x^(1/4) your equation becomes much easier to look at:

x^(1/2)-3x^(1/4)-4 = 0
u^2 - 3u - 4 = 0

solve for u, and then x = u^4

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