We use quadratic formula then
For a expression
The quadratic formula is

If underroot values becomes negative we use iota(i)
which has value=√-1
Nothing multiplies to 18 and adds to -10
B)Emily either switched the signs for no reason or solved it in the incorrect order
C) The sudent solved the equation in an incorrect order. Emily solved the first, then third, then second, which was the incorrect order. Edgar solved the thirst root, then second, then third, thus he is correct.
26/100 or simplified to 13/50
For Question 1 the answer is the last choice.