Question

x+1=9x^3 + 9x^2

Answer 1

factor the gcf right side

Answer 2

9x^3+9X^2-x-1+0
9x^2(x+1) -1(x+1)
9x^2-1=0 x+1=0

Answer 3

yes or no?

Answer 4

yes

Answer 5

45x^-x-1

Answer 6

now solve it

Answer 7

thank u ranthanreddy, i have help already

Answer 8

9x^3+9X^2-x-1+0
9x^2(x+1) -1(x+1)
9x^2-1=0 x+1=0

Answer 9

on the right its going be x=-1

Answer 10

lost on left side!

Answer 11

9x^3+9X^2-x-1 = 0
9x^2(x+1) -1(x+1) = 0
9x^2-1=0 x+1=0

9x^2 =1, x = -1

x^2 = 1/9, x = -1

x = 1/3, -1/3, x = -1

overall, x = {1/3, -1/3, -1}

Answer 12

since we did the sq rt thats how u get a pos and neg?

Answer 13

yes

Answer 14

x^2 = 1/9

x = \(\pm \sqrt{1/9}\)

Answer 15

i b lost in math, how am i supposed to know when a problem has 1 or 2 or 3 different answers?

Answer 16

9x^2-1=0
(3x + 1)(3x - 1) = 0
set each factor be zero then solve for x

Answer 17

here, highest power is 3, so you will have 3 answers MOST of the time

Answer 18

you will NEVER have more than 3 answers - thats for sure

Answer 19

but in quadratic 2x^3+3x^2+5x+5=0 has only 2 answers

Answer 20

its a cubic, it will have 3 answers

Answer 21

true or false?

Answer 22

quadratic means, highest power is 2

Answer 23

so 2x^2+3x-4=0
has only 2 answers?

Answer 24

it can have 2 or 1 answer

Answer 25

only thing we can say for sure is :-
it cannot have more than 2 answers

Answer 26

the ones that has 3
does it mean they can have up to three or always has three?

Answer 27

exactly, they can have upto three answers

Answer 28

cubic equations can have upto 3 answers
quadratic equations can have upto 2 answers

Answer 29

so, i have to go back and plug in the answers in the original equation to see if they work?

Answer 30

not needed

Answer 31

and if they dont, throw away and not include in ultimate answer?

Answer 32

once you solve, you will end up with 3 or 2 or 1 answers. they will be the answers.

Answer 33

what not needed?

Answer 34

not needed to plug them back and check

Answer 35

oh, i see....but i seen professor plugging back in the equation, i coulda swore a number didnt work and he didnt include in answer

Answer 36

for the first problem we got 3 answers :-
x = {1/3, -1/3, -1}

they're the answers, we dont need to plug them back in equation and check if they satisfy or not.

Answer 37

im new to site, how can i give you merit?

Answer 38

here is the thing :-
plugging back is NOT necessary for quadratic/cubic equations
plugging back is necessary for radical equations

Answer 39

you have been very resourceful this morning, my night....thank you so much...wish i could have you as tutor

Answer 40

cuz, radical equations give you extraneous solutions, so you must always verify the answers u got by plugging them in the given equation, and throw away those that dont satisfy

Answer 41

for quadratic/cubic, we never plug them back. cuz there wont be any extraneous solutions.

Answer 42

radical equation has sq rt in original problem
?

Answer 43

yes !

Answer 44

how can i give you merit for your help?

Answer 45

when u h ave sqrt, and u square... then u wil endup with extraneous solutions, you need to check domain continuously at each step

Answer 46

np :) im fine

Answer 47

u sure. i see u only asked 9 questions but answered almost 300

Answer 48

lol i have another account where i ask all crazy questions i get

Answer 49

thats silly!

Answer 50

:)

Answer 51

well, wishful thinking says "i wish i could contact you for more help"

Answer 52

thanx a million see ya

Answer 53

sure just holler when you feel stuck :) cya