Finite Mathematics question 18

Mathematics
Tutor: None Selected Time limit: 1 Day

Solve the system of linear equations using the Gauss-Jordan elimination method.

7x + 5y = 32

-3x + y = -20

Oct 20th, 2015

Thank you for the opportunity to help you with your question!

we need to change the equations or put them in gaus-jordan method

7   5    32

-3   1     -20                      ...........I can't draw the lines here, but i will try to make everything clear

we need to end with this type of this form

0        1      x

1         0      y

to change 7 to 1, we need to multiply the whole equation by 1/7

we end up with 

1  5/7  32/7.........................in the first row

to change -3 to zero, we multiply 3 with 1 (from first row) then add top the second row

..........................more to follow, time ran out dear, but will deliver everything! 


Please let me know if you need any clarification. I'm always happy to answer your questions.
Oct 20th, 2015

the zero on the second row will be obtained after adding 3 to eliminate -3

0    22/7  -44/7

Oct 20th, 2015

So what is the answer, I am still confused? Here are the multiple choices I was given below:

A. (7, -3)

B. (6, -2)

C. (2, -6)

D. (-6, 2)

E. (-7, -2)

Oct 20th, 2015

no need to replace the second character in R2 since it's already 1

so we now change the second character on R1 (5) to zero!

-5 x 1 then add to 5 gives us zero

-5 x 32/7= -204/7

The full equation after elimination

1      0    32/7

0      1    -204/7




Oct 20th, 2015

x=32/7

y=-204/7

Oct 20th, 2015

sorry  i did other things...let me answer you asap!

Oct 20th, 2015

C. (2, -6)

Oct 20th, 2015

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Oct 20th, 2015
...
Oct 20th, 2015
May 23rd, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer