Question 1144691
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Note it is common practice to denote exponentiation using the ^ (shift-6) symbol....<br>
{{{x^400 = 9^1000}}}
{{{x^(400/400) = 9^(1000/400)}}}
{{{x = 9^(5/2) = (3^2)^(5/2) = 3^5 = 243}}}