Answer: yes, she did made an error, a very big mistake.
Step-by-step explanation:
first, we have varieties of ways in which we can use to solve this, the most important thing is to stick to the mathematical rules of solving any equations.
using the most simpler method
-4x + 11 = 6x + 1
collect like ter
-4x -6x = 1 - 11
-10x = -10
divide bothside by -10
-10x/-10 = -10/-10
x=1
secondly, using the method she is intending to use, its more easier to subtract 6x from bothside
-4x + 11 = 6x +1
-6x -6x
_______________
-10x + 11 = 1
-10x = 1-11
-10x = -10
x = 1
or still we can doing it exactly as she did, but it will take us through a long way i.e by adding +6
-4x + 11 = 6x + 1
+6x +6x
_______________
2x +11 = 12x +1
2x-12x = 1-11
-10x=-10
x=1
