Question

may ou describe and correct the error in solving for one of the variables in the linear system -x + 4y = -9 and 3x - 2y = 7

Answer 1

The error lies in the beginning of step 2

-x was substituted in the place of x in first line of step 2

Correction of the error and solution is given below

Step 1

-x + 4y = -9

-x = -4y -9

multiply both sides by -1, we have

x = 4y + 9

Step 2

3( 4y + 9) -2y =7

12y +27 -2y = 7

10y +27 = 7

10y = 7-27

10y = -20

y = -20/10

y = -2