the 4 in line 5 to line 6 should not be divide , rather is should be minus
There is a mistake at line 6.At RHS of the equation, it should be 4/7 not 7/4. So it should be x = 4/7.
The error is in line 5 to 6, the error is in 4=7x becomes x=7/4 it should be 4=7x becomes x=4/7
The err in in line 6 as the 4=7x should be x=4/7
In line 6, It should be 4/7 not 7/4.So it should be x = 4/7.
Line 6: It should be 4/7 instead of 7/4. He must have been confused as he put the unknown terms on the right instead of the left