Zacharias is using the quadratic formula to solve the equation 0 = –2x2 + 5x – 3. he begins by substituting as shown. quadratic formula: x = startfraction negative b plus or minus startroot b squared minus 4 a c endroot over 2 a endfraction substitution: x = startfraction negative 5 plus or minus startroot 5 squared minus 4(2)(negative 3) endroot over 2(negative 2) endfraction what error did zacharias make? the –5 should be 5. the 52 should be –52. the 2 in the numerator should be –2. the 2 in the denominator should be –2