Question

Please help (Quadratics)

Answer 1

@Nnesha

Answer 2

@RCCB

Answer 3

\[\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\]

Answer 4

@bluediamond1999

Answer 5

Start by plugging 7 in for a, -2 in for b, and -1 in for c in the quadratic formula.

Answer 6

The solution I got is not one of the answer choices. :-( I'm so sorry.

Answer 7

Ax^2+Bx+C=0
quadratic equation where
a=leading coefficient
b= coefficient of x term(middle term)
c=constant
so
a , b, c are what in ur equation ?

Answer 8

are you there ? o.O

Answer 9

ah i just saw blue is already mentioned what a , b and c are
so just plug them into the formula

Answer 10

oh**

Answer 11

sorry, I was away from the computer.

Answer 12

This question has been open for an hour xD

Answer 13

When I plug it in, the solution I got didn't match the answer choices.

Answer 14

alright show your work
all steps so i'll try to find out the mistake

Answer 15

\[\frac{ -7+\sqrt{7^2-4(7)(-1)} }{ 2(7) }\]

Answer 16

hmm what is B in the original equation ?
remember b is coefficient of x term not x^2 term

Answer 17

\[-2\pm \sqrt{-2^2-4(7)(-1)}\]

Answer 18

there is a a liittle mistake b is -2 and there is already negative at front of b in the formula so it would be \[\large\rm \frac{ -(\color{Red}{-2})+\sqrt{(\color{ReD}{-2})^2-4(7)(-1)} }{ 2(7) }\]
and please put parentheses (-2)^2 not -2^2

Answer 19

now simplify that :=))

Answer 20

\[-(-2)\pm \sqrt{32}\]

Answer 21

\[(14)\]

Answer 22

right how would you simplify -(-2) = ?
it's same as -1(-2)=?

Answer 23

and factor 32
find two factor of 32 one of them should be perfect square

Answer 24

hmm no -1(-2) means -1 times -2

Answer 25

alright, 2

Answer 26

right. what are the factors of 32 ?

Answer 27

1,2,4,8,16,32

Answer 28

right we need greatest common factor and it should be the prefect square root
meaning when you take square root of that number you should get perfect number not decimal so which one would you pick ?

Answer 29

16

Answer 30

right so we can rewrite 32 as 16 times 2
\[\rm \frac{ 2 \pm \sqrt{16*2} }{ 14 }\]
take square root of 16
square root of 16 is 4
\[\rm \frac{ 2 \pm 4\sqrt{2} }{ 14 }\]

now take out the common factor from the numerator

Answer 31

\[-2+\sqrt{6}\]

Answer 32

\[\frac{\color{Red}{ 2} \pm \color{blue}{4\sqrt{2}} }{ 14 }\]
red=first term
blue= 2nd term
what is common in both terms ?

Answer 33

2

Answer 34

right take it out and then simplify let me know what you get after this

Answer 35

hmm 6 ??
what would you get when u take out 2 from (2 plus/minus 4 sqrt{2} ) ??

Answer 36

5.656

Answer 37

in other words when we take out common factor basically we divide it (2 +/- 4sqrt{2}) by 2

Answer 38

3.82

Answer 39

-sighs-

Answer 40

no don't use calculator

Answer 41

here is an example \[\rm 3x+6\] 3 is common factor so i'll take it out by dividing both terms by 3(common factor)\[\rm \frac{ 3x }{ 3 }+\frac{6}{3} \rightarrow 3(1x+2)\]

Answer 42

so by looking at that example what would you get when utake out 2 from (2 +/- 4sqrt{2})

Answer 43

\[\frac{ 2x }{ 2 }+\frac{ 4 }{ 2 }\rightarrow2(1x+2)\]

Answer 44

it's \[\frac{ \color{ReD}{2 \pm 4\sqrt{2} }}{ 14 }\]
so divide \[2 \pm 4\sqrt{2}\] by 2 first to take out the common factor

Answer 45

Wow. I'm really bad at this.

Answer 46

\[\large\rm x= \frac{ \color{Red}{\frac{2}{2} \pm \frac{4\sqrt{2}}{2}} }{ 14 }\]
we are taking 2 from (2 +/- 4sqrt{2})

Answer 47

\[-1+2\sqrt{2}\]

Answer 48

how did you get -1 ???

Answer 49

oops it would be positive 1

Answer 50

right \[\frac{ 2(1 \pm 2\sqrt{2}) }{ 14 }\]
and we write the common factor front of the parentheses
now simplify

Answer 51

\[\frac{ 1+(2)\sqrt{(2)} }{ 7 }\]

Answer 52

right but it's plus/minus two solution not just one

Answer 53

Okay

Answer 54

Thank you, Nnesha.

Answer 55

np, practice and practice and then finally u will be able to understand this !!