Question

What error did zacharias make?

Answer 1

The 2 in the numerator should be -2.

Explanation:

We are given that a quadratic equation

-2x^2+5x-3=0

We have to find error made by Zacharias.

We have a=-2,b=5,c=-3

Quadratic formula : D=b^2-4ac

Substitute the values in the given formula

D=(5)^2-4(-2)(-3)

Therefore, the 2 in the numerator should be -2 .This is the error made by Zacharias.

Answer 2

The equation 0 = -2x2 5x - 3 was the quadratic formula that Zacharias used. However, he started substituting as:
Quadratic formula as x = ; substitution as x

The errors he made: he mistakenly used the negative (-) and postive (+)
* -5 should have been 5
* 52 should have been -52
* both the numerator and the denominator should have been -2 instead of 2