Question

for these three equations
x^2-4x+3=0
x^2-7x+2=20
x^2-3x=1

solve at least one by factoring
solve at least one by using the quadratic formula
solve the last one with either of the two options

Answer 1

solve the second one by factoring and the last one by factoring also the first one you need to solve with quad eq.

Answer 2

First of all they all need to = 0.
The first two should be factoring.. the last one is quadratic formula.

Answer 3

x^2 - 4x + 3 = 0 Hint (3 * 1 = 3) (3 + 1 = 4)

Answer 4

1. (x - 3)(x - 1)

Answer 5

yea hes right i copied in diff order

Answer 6

x^2 - 7x + 2 = 20
x^2 - 7x - 18 = 0 Factors of 18 that subtract to give you 7

What are they?

Answer 7

x^2 - 3x - 1 = 0 the reason you use the quadratic formula is because there are no factors of 1 that subtract to give you 3.

Answer 8

Confused.. what are the solutions to #1 if (x - 3)(x - 1) = 0

Answer 9

3 and 1????

Answer 10

Very good

Answer 11

Now on the 2nd one... the factors of 18 are
1 * 18
2 * 9
3 * 6

which pair subtracts to give you 7

Answer 12

2 and 9

Answer 13

good so you have (x - 9)(x + 2) = 0

what would be your answers for x

Answer 14

9 and-2

Answer 15

Very good.

Now we need to do the quadratic formula.. do you know what that is? yes/no

Answer 16

i think so

ax^2+bx+c

Answer 17

well.. you have to get it in this form first.. so we have

x^2 - 3x - 1 = 0

what are
a?
b?
c?

Answer 18

a=1
b=-3
c=-1

Answer 19

Good.

the formula is

x = -b +- sqrt(b^2 - 4ac) all over 2a

Have you seen this the +- means a + with a - sign under it.

Answer 20

yes

Answer 21

-b I like to read as the opposite of b so the opposite of -3 is +3

Answer 22

x = 3 +- sqrt((-3)^2 - 4(1)(-1)
------------------------
2(1)

Answer 23

x = 3 +- sqrt(9 +4)
-------------
2

do you see how I got this? the (-4)(1)(-1) is a + 4

Answer 24

yes

Answer 25

OK.. so your answer is

x = 3 +- sqrt(13)
-----------
2

Answer 26

so 4.80 and 1.20

Answer 27

I don't think so..

Answer 28

If you are using a calculator put in
(3 + sqrt(13))/2
(3 - sqrt(13))/2

Answer 29

3.307

Answer 30

-3.027

Answer 31

Oops.. -.3027

Answer 32

but those aren't the answers those are approximations since the sqrt(13) is irrational