Answer:
Barbara's did not factor out 63.
Step-by-step explanation:
63 can be factorize as 63 = 7 [tex]\times\\[/tex] 9 and 7 d can be factorize as 7 d = 7 [tex]\times\\[/tex] d
Therefore common term between 7 d and 63 is 7.
[tex]\therefore 7 d + 63 = 7\left(d+9\right)[/tex].
In Barbara's equation, it did not factorize 63 as it contains common term 7 in it. Therefore that is the error in Barbara's equation.
