Question

zacharias is using the quadratic formula to solve the equation 0 = –2x2 5x – 3. he begins by substituting as shown. quadratic formula: x = substitution: x = 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

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`

Then,
`x=(-b\pm√(D))/(2a)`

Substitute the values in the given formula

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

`x=(-5\pm√((5)^2-4(-2)(-3)))/(2(-2))`

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

Answer 2

the equation -2x² + 5x -3=0, we notice that the sum of the coefficient equals 0, -2+5-3=0, if such a case happens, the solution of the previous equation will be, x=1 (always) and x= c/a, a=-2, and c=-3, so x=-3/-2, finally, the answer is: the 2 in the denominator should be -2