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Answer:
no mistakes
Step-by-step explanation:
There are no mistakes in the derivation of the quadratic formula by completing the square
Step 1
Move c to the right hand side
Step 2 Get x^2 to have a coefficient of 1
Step 3 complete the square by adding ( b/2a) ^2 to each side
Step 4 Write in the completed square form ( x+ b/2x) ^2 = -c/a + ( b/2a) ^2
Step 5 take the square root of each side, remembering the plus and minus
Step 6 subtract (b/2a) from each side