Mistake in expression
A student made a mistake while attempting to multiply the expression (2 - 5i)(5 + 2i).
(2 - 5i)(5 + 2i) = 10 + 4i - 25i - 10i2
= 10 + 4(-1) - 25(-1) - 10(1)
= 10 - 4 + 25 - 10
= 21
Complete the explanation and correct the error.
Hint: The student incorrectly defined i as being equal to ___ instead of ___. The student should have written the product as :
Your answer:
(2 - 5i)(5 + 2i) = 10 + 4i - 25i - 10i2
= 10 + 4(-1) - 25(-1) - 10(1)
= 10 - 4 + 25 - 10
= 21
Complete the explanation and correct the error.
Hint: The student incorrectly defined i as being equal to ___ instead of ___. The student should have written the product as :
Your answer:
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