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

The 2 in the numerator should be –2

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(+/-)√(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