A partial solution to I1-xI-3 =- 1 is shown below.
Step A I1-xI-3 =- 1
Step B I1-xI = 2
Step C 1+x=2 or -1+x=2
Step D x=3 or x-1
Where was the first mistake made if there is one?
C
1-x or x-1
Step A I1-xI-3 =- 1
Step B I1-xI = 2
Step C 1+x=2 or -1+x=2
Step D x=3 or x-1
Where was the first mistake made if there is one?
1-x or x-1