2023 AMC 12B Problems/Problem 12

Revision as of 16:33, 15 November 2023 by Failure.net (talk | contribs)

Problem

For complex number $u = a+bi and$v = c+di$(where$i=\sqrt{-1}$), define the binary operation$u \earth v = ac \plus bdi$$ (Error compiling LaTeX. Unknown error_msg)\textbf{(A) }\frac{9}{25}\qquad\textbf{(B) }\frac{1}{9}\qquad\textbf{(C) }\frac{1}{5}\qquad\textbf{(D) }\frac{25}{169}\qquad\textbf{(E) }\frac{4}{25}$