Question

please help

Answer 1

Solve x2 - 7x = -13

Answer 2

First add 13 to each side to get

x^2-7x+13

And to solve for 0 you will have to use the quadratic formula

Answer 3

idk how to do that

Answer 4

Okay so the quadratic formula is: \[\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\]

Answer 5

And you have a quadratic equation in standard form:

a^2+bx+c

You have:

x^2-7x+13 so:

a=1
b=-7
c=13

Answer 6

ohh

Answer 7

Yeah so you plug in the corresponding numbers and solve: \[\frac{ 7 \pm \sqrt{-7^2-4(1)(13)} }{ 2(1) }\]

Answer 8

howd you get -4

Answer 9

That's just a part of the quadratic formula

Answer 10

The -4ac part

Answer 11

oh my bad

Answer 12

-4*1*13 is -52

-7^2 is 49 so now we have: \[\frac{ 7 \pm \sqrt{49-52} }{ 2 }\]

Answer 13

is that it?

Answer 14

in all of the answers there is an i

Answer 15

Not yet

So now we have: \[\frac{ 7 \pm \sqrt{-3} }{ 2 }\]

And we cant take the square root of a negative number. If you recall, i^2=-1.
So we'll have: \[\sqrt{3*i^2}\] which would be -3 and the square root of i^2 is just i so now we're left with the answer of: \[\frac{ 7 \pm i \sqrt{3} }{ 2 }\]

Answer 16

thanks

Answer 17

You're welcome

Answer 18

can you help me with something else

Answer 19

Yeah sure if I can

Answer 20

ive got a final coming up this week thats worth 275(20%) ...it has 36 multiple choice and 4 free response.. i have to get a 60% on the final or i dont get credit for the class. how many questions do you think i would have to get right to get a 60%

Answer 21

not really a math question

Answer 22

Probably about 20+ right

Answer 23

hmm thats going to be impossible for me

Answer 24

thanks for the help

Answer 25

You're welcome