Question

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

Answer 1

Answer: d on edge2020

Step-by-step explanation: no cap

Answer 2

Answer:

The 2 in the numerator should be –2

Step-by-step explanation:

we know that

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-2x^{2} +5x-3=0$  

so

$a=-2\\b=5\\c=-3$

substitute in the formula

$x=\frac{-(5)(+/-)\sqrt{5^{2}-4(-2)(-3)}} {2(-2)}$

$x=\frac{-5(+/-)\sqrt{25-24}} {-4}$

$x=\frac{-5(+/-)1} {-4}$

$x=\frac{-5(+)1} {-4}=1$

$x=\frac{-5(-)1} {-4}=1.5$

therefore

The 2 in the numerator should be –2