Question 128789
sqrt (98x^5) - 2x sqrt (18x^3)

= sqrt[49x^4*2x] - 2x sqrt[9x^2*2x]

= 7x^2*sqrt(2x) - 2x*8x*sqrt(2x)

= [7x^2-16x^2]*sqrt(2x)

= -9x^2*sqrt(2x)


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Cheers,
Stan H.