Question

I am really stuck on this and need some help :
Solve system :
4x1 + x2 = -5
16x1 + 4x2 = -20

Answer 1

Are the numbers after x powers?

Answer 2

Did you mean to put in y's for each second x as well?

Answer 3

prime?

Answer 4

are you just looking to solve for the system? because it will be no solution

Answer 5

if that's algebra...

Answer 6

no
it says solve the system and its a matrix problem

Answer 7

oh matrix lol :p

Answer 8

the space for the answers says [x1] [x2] =
[1]
[s]

Answer 9

linear algebra then?

Answer 10

am I the only one noticing its the same equation twice... there are infinite solutions

Answer 11

Do you guys know any calculus ? One of my answers was 0,1 for the bottom row and the answer was accepted

Answer 12

?

Answer 13

No help att all? You guys say its simple I am giving the right format

Answer 14

a possible answer is (x1,-5-4*x1), x1 (element of domain)

Answer 15

What? I need the answer in a 2 x 2 matrix

Answer 16

I know you probably did it right? But I do't get what that has to do with the answer?

Answer 17

ok, so the matrix should represent the linear transformation?

Answer 18

Yeah, I mean it says nothing about transformations but here is the exact wording
Solve system 4x1 + x2 = -5
16x1 +4x2 = -20
[x1] =

[x2] = 0 , 1 <------ solution I got for bottom row

Answer 19

is something like this
[4 1 -5]
[16 4 -20]

Answer 20

^YES Andresfon12

Answer 21

Andresfron you got it!

Answer 22

I had that too but

Answer 23

I don't get how to solve by Gaussian for x1 and x2

Answer 24

let think because did some problem like that last year

Answer 25

ok

Answer 26

just row reduce the matrix

Answer 27

If it helps I used Gaussian and got
1 , 1/4 <----- top row
0 , 0

Answer 28

Right but after I row reduced its not accepting my answer how do I write it?

Answer 29

what did you get for an answer?

and what does your program accept for infinite solutions?

Answer 30

I recall it

Answer 31

Can you do out the reduction how do I work with the system to find x1 and x2 and write answer as 2 x 2 matrix

Answer 32

need to multiply

Answer 33

I got
1 1/4
0 0

Answer 34

thats just the left side; do the right side as well

Answer 35

No you need to row reduce the augmented matrix not just the matrix A

Answer 36

ok right side is -5
60

Answer 37

Then there is no solution.

Answer 38

augment (A|b) into (I|x)

Answer 39

ir something similar

Answer 40

I am so lost

Answer 41

row redudion at the bottom

Answer 42

Can you write this with the numbers?

Answer 43

you dont get 0+0 = 60 for starters

Answer 44

Yeah I know my bottom row solution was 0, 1

Answer 45

That's what the asker got.

Answer 46

My bottom row solution of 0, 1 was accepted

Answer 47

my top row was not accepted as correct thats what I mainly need help with

Answer 48

i get like [0 4 0] for the bottom

Answer 49

4x1 + x2 = -5
16x1 + 4x2 = -20


1 1/4 | -5/4
0 0 | 0

Answer 50

^ I got that part Amistre

Answer 51

sorry im wrong

Answer 52

Here is a tip. The first row is a multiple of the second row. From this you can tell that there will be a zero row which means that there will be a free variable which mean.s that if there is a solution then there will be an infinite number of solutions

Answer 53

\[\binom{x_1}{x^2}=\binom{-5/4}{0}+x_2\binom{1/4}{1}\]

Answer 54

forgot my negative' -1/4

Answer 55

i agree with amistre64

Answer 56

one answer is [-5/4 , 0]

Answer 57

Yes that was accepted!

Answer 58

all the other answers are that + multiples of the other one

Answer 59

i also agree with @amistre64

Answer 60

but there is an infinite number of solutions.

Answer 61

Thank you so much amistre

Answer 62

yep

Answer 63

Where was I going wrong?

Answer 64

is all about multiply and dividing

Answer 65

Like I know you probably have to go I am sorry

Answer 66

without knowing what your program looks like, i wouldnt know where to begin; prolly tho in the parametric setup

Answer 67

since we have a free variable; that portion is only equal to itself and nothing else ...

Answer 68

Yeah that is true

Answer 69

So there is a unique solution? only one solution?

Answer 70

there is a .... homogenous solution and a particular solution , maybe lol

Answer 71

hahaha

Answer 72

JAJAJA

Answer 73

LOL

Answer 74

I always thought rows of 0's means inconsistent but whatever i guess

Answer 75

when does 0 equal 0 ?

Answer 76

Wait I don't get it. What's the answer?

Answer 77

read the defintion in your text book

Answer 78

0=0 is always consistent

1=0 has one solution

0=1 never

Answer 79

alright I will go over the concepts again

Answer 80

Yeah you are right

Answer 81

Gotcha bro.

Answer 82

i'd love to say the answer is 42 but it's already been answered and it's too cliched =))