Question 658799
1) {{{(2-7i)^2}}}
{{{(2-7i)(2-7i) = 4 - 14i - 14i + 49i^2}}}
{{{4 - 28i + 49i^2}}} knowing i={{{sqrt(-1)}}}, then {{{i^2 = sqrt(-1)^2 = -1}}}
{{{4 - 28i + 49(-1) = 4 - 28i - 49 = highlight_green(-45 - 28i)}}}
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2) {{{sqrt(396x^8y^19) = sqrt(9*4*11*x^4*x^4*y^9*y^9*y) = 3*2*x^4*y^9sqrt(11y)}}}
{{{highlight_green(6x^4y^9sqrt(11y))}}}
...
3){{{(8x^3)^(-1/3) = 1/((8x^3)^(1/3)) = 1/(root(3,8x^3)) = highlight_green(1/2x)}}}

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