Can the quadratic formula be solved without and a? b? or c?

Question

Francisco claimed that the equation x 2 – 8x = 0 cannot be solved by the quadratic formula since there is no value for c. What are his misconceptions?

 Francesca claimed that the equation x 2 – 19 = 0 cannot be solved using the quadratic formula because there is no value of b. What are her misconceptions?

Answer 1

x² - 8x = 0

x² - 8x + 0 = 0

c = 0

You can see that the quadratic formula can be used. Now apply the same kind of reasoning above to show that Francesca is wrong. Hint: b=0.