Question

How do I solve problems like this? I have a math exam coming up, and I want to be prepared for solving problems like this.

Please explain the process to me. Thanks!

What are the exact solutions of x^2 - 5x - 7 = 0?

I'll post the answer choices in the options. Thanks again!

Answer 1

@ganeshie8 @mathmale @mathstudent55 @zepdrix @triciaal

Answer 2

familiar with quadratic formula ?

Answer 3

A. \[x = \frac{ -5 \pm \sqrt3 }{ 2 }\]

B. \[x = \frac{ 5 \pm \sqrt3 }{ 2 }\]

C. \[x = \frac{ -5 \pm \sqrt53 }{ 2 }\]

D. \[x = \frac{ 5 \pm \sqrt53 }{ 2 }\]

Answer 4

@ganeshie8 I am

Answer 5

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

@ganeshie8 That's the quadratic equation, right?

Answer 6

*formula

Answer 7

@ganeshie8 ?

Answer 8

Oh, do I need to fill in the formula to solve the problem?

Answer 9

Yes

Answer 10

x^2 - 5x - 7 = 0

a = ?
b = ?
c = ?

Answer 11

@ganeshie8 Sorry, for the late response, I'm helping someone else on their homework, I'll be back in about 1 minute, I'm almost done.

Answer 12

@ganeshie8 Well that took 5 minutes, but I'm back

Answer 13

a = 1

b = -5

c = -7

Answer 14

Looks good. Plug them in

Answer 15

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

Answer 16

1^2 = 1.

-4*1 = -4. -4 * -7 = 28.

2 * 1 = 2

Answer 17

thats wrong, check once..

Answer 18

\[x = \frac{ -1 \pm \sqrt{1 - 28} }{ 2 }\]

Answer 19

1 - 28 = 27

Answer 20

b = -5 right ?

Answer 21

Oh, that's wrong?

Answer 22

Gaah OS IS FREAKING OUT.

What did I get wrong @ganeshie8 ?

Answer 23

Yeah, b = -5

Answer 24

OHHHH

Answer 25

\[x = \frac{ 5 \pm \sqrt{(-5)^2 - 4(1)(-7)} }{ 2() }\]

Answer 26

I didn't even type in that order. wtf is going on @ganeshie8 ?

Answer 27

Wait, now it's correct order again. NVM

Answer 28

-5^2 = 25. 4ac = 28.

25 - 28 = -3.

\[x = \frac{ 5 \pm \sqrt{-3} }{ 2 }\]

Answer 29

@ganeshie8 Is that correct?

Answer 30

@ganeshie8 ?

Answer 31

@ganeshie8 If u've already typed something, I can't see it. OS Is lagging like crazy and idk why

Answer 32

\[x = \frac{ 5 \pm \sqrt{(-5)^2 - 4(1)(-7)} }{ 2(1) } = \frac{5\pm \sqrt{25+28} }{2} \]

Answer 33

Why 25 + 28?

its b^2 - 4ac

doesnt the - sign stick with the 4ac

making it

-4acac?

Answer 34

*-4ac

Answer 35

@ganeshie8 i know this isnt on my own post, but when youre done here do you think you could help me on my post?

Answer 36

@cadenblah Just send him a message

Answer 37

@ganeshie8 Help? Why would it be 25 + 28?

Answer 38

@ganeshie8

Answer 39

@ganeshie8 Wanna go on PeeraAnswers or something?

Answer 40

@ganeshie8 It doesn't matter I think I get how to solve the problem. I'll just use a calculator or something. I know how to get to the answer, and that's what matters. Thanks again!!!

Answer 41

Refer to the attachment.