X discounted 30% is 42. What is x?
2 answers:
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<u>Answer:</u>
The correct answer option is 0.
<u>Step-by-step explanation:</u>
We know the quadratic formula that we use to find the roots of a quadratic equation:
The discriminant in this formula is the part underneath the square root symbol i.e. b^2-4ac.
For a quadratic equation to have exactly one real number solution, the discriminant must be zero.
As we can see the + and - sign appearing before the discriminant here so for one real number solution, these plus and minus signs need to be removed which can only happen if we have a value of zero.