Final answer:
The equation -08 + r is being questioned for errors. After reviewing the provided context, it is possible to subtract 8 from a negative number, and it appears there is no error within the context given, making option c) 'the equation has no error' the likely answer.
Step-by-step explanation:
The question asks to identify the error in the given mathematical equation. From the information provided, the equation appears to be presented as part of solving a quadratic equation using the quadratic formula. The quadratic formula is x = \(\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\). In this scenario, the given values of a = 3, b = 13, and c = -10 suggest that work is being done to solve a quadratic equation. If we substitute these values into the quadratic formula, we get:
x = \(\frac{-13 \pm \sqrt{(13)^2 - 4 \cdot 3 \cdot (-10)}}{2 \cdot 3}\)
There seems to be no mathematical error with the approach of subtracting 8 from a negative number or involving complex numbers here. Without the complete equation, it's challenging to identify the specific error, if one exists.
However, if the student meant \(-08 + r\) then option b) would be incorrect as it's possible to subtract 8 from a negative number, making option c) the likely answer: the equation has no error.