Which of the following cannot be solved using the quadratic formula?

Answer:
C
Step-by-step explanation:
Quadratic formula is used only to solve the quadratic equations .
Means the equation of the form
[tex]ax^{2} +bx+c=0[/tex]
In this the x^2 part is must because that only makes the equation a quadratic.
Looking at the four options given to you , only the option C has the missing x^2 term, which makes it a linear equation and hence the quadratic formula cannot be applied there .
So the right option for your question with the quadratic formula is
option
C