Question

2x^2+3x=11 using quadratic formula

Answer 1

First things first...do you know the quadratic formula?

Answer 2

yes

Answer 3

Ok, then secondly, you need that polynomial in standard form. That means that you need to move the 11 over to be with thee rest of the equation.

Answer 4

\[2x ^{2}+3x-11=0\]

Answer 5

okay i have that written down. what is next ?

Answer 6

Here is the formula for a = 2, b = 3, c = -11:

Answer 7

\[\frac{ -3\pm \sqrt{(3)^{2}-4(2)(-11)} }{ 2(2) }\]can you do that math?

Answer 8

do inside the radical sign first...

Answer 9

okay i did and i got 88+9

Answer 10

which is what? what does that equal?

Answer 11

equals 97

Answer 12

my answer choices are 0 1 and 17

Answer 13

That's right and is 97 have a perfect square?

Answer 14

we are not to the answer stage just yet...

Answer 15

no it doesnt

Answer 16

so we have this then:\[\frac{ -3\pm \sqrt{97} }{ 4 }\]and if your problem was typed here correctly, that is the answer. It is not 0, 1 or 17.

Answer 17

let me check myself right quick...

Answer 18

What is the value of b2 - 4ac for the following equation?

2x2 + 3x = -1

Answer 19

this is the problem

Answer 20

you are looking for the discriminant of 2x^2, + 3x = -1?

Answer 21

if that ios the value of b2-4ac than yes

Answer 22

I thought you were to factor the problem with the -11 in it? which is it? finding b^2-4ac is the discriminant.

Answer 23

Ok, redo.

Answer 24

This is the problem...yes?\[2x ^{2}+3x=-1\]

Answer 25

a = 2, b = 3, c = +1 (when you move it over to put the equation into standard form)

Answer 26

The discriminant is \[b ^{2}-4ac\]which is, using your values,\[(3)^{2}-4(2)(1)\]That equals 1.

Answer 27

your answer is 1. It is there in your choices.