Question

${x}^{2} + 4 \sqrt{ {2x}^{4 } } - {x}^{3} + {9x}^{2} + 4$

Answer 1

x^2 + 4√(2x^4) - x^3 + 9x^2 + 4

= x^2 +4*√2 * x^2 - x^3 + 9x^2 + 4

= - x^3  + 10x^2 + 4√2 x^2 + 4

= -x^3 + 2x^2( 5 + 2√2) + 4