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5n2+100=30n , need help explaining how you would work this out

1 Answer

2 votes

Answer:

n = 3 + i√11 , 3 - i√11

Explanation:

This is a quadratic equation and the first step is to write it in standard form:

5n^2 - 30n + 100 = 0

Divide through by 5:

n^2 - 6n + 20 = 0

Completing the square:-

(n - 3)^2 - 9 + 20 = 0

(n - 3)^2 = -11

n - 3 = i√11 or - i√11

n = 3 + i√11 , 3 - i√11

(2 complex roots).

User Julien TASSIN
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