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HELP

M Home Ivy Tech Commu x MyMathLab MATH135 x Take a Test- Ray Kim C Chegg study IGuided x C searc Textbook Solutior x Solved: Sohe the folowi x C 9H1 H https//www.math Sol ship Print Fvents Kelley ralend Fvent MATH135-84 Spring 2017 Quiz: MIDTERM QUIZ This Question 1 pt 7 of 33 (1 Complete Solve using augmented matrices Select the correct choice below and il neoessary, fil in the answer box to complete your choice O A. The unique s is arid x O B. The system has infinitely many solutions. The solution is x1- and x (Sinpily your answer. Tvpe an expressivri using las Uhe variable. O C. There is no solution. Click to select and enter your answers. a Search Windows In For Yoo Ray Kim 5/12/17 11:31 AM Submit Quiz This Quiz: 33 pts possible 1132 2017-U5-12

Explanation / Answer

2x1 + x2 = 7

x1 - x2 = -4

Answer:

2 1 | 7

1 -1 | -4

Find the pivot in the 1st column and swap the 2nd and the 1st rows.

1 -1 | -4

2 1 | 7

Multiply 1st row by 2

2 -2 | -8

2 1 | 7

Subtract the 1st row from the 2nd row and restore it.

1 -1| -4

0 3|15

Make the pivot in the 2nd column by dividing the 2nd row by 3

1 -1|-4

0 1| 5

Multiply the 2nd row by -1

1 -1| -4

0 -1| -5

Subtract the 2nd row from the 1st row and restore it

1 0 | 1

0 1 | 5

So the solution is x = 1, y =5

Option A is correct.

The unique solution is x = 1 and y = 5

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