When solving an equation, Gabrielle's first step is shown below. Which property justifies Gabrielle's first step?

Option C is correct.
We have the two following equation -
[tex]x^{2} +(6x^{2} +5)=5x^{2} -4[/tex]
We have to find out which property justifies Gabrielle's first step.
According to associative property of addition changing the grouping of addends does not change the sum.
For example - ( 2 + 3 ) + 4 = 2 + ( 3 + 4 )
According to the question, on the left hand side, we have -
[tex]x^{2} +(6x^{2} +5)[/tex]
Using the associative property of Addition, we can write the above expression as -
[tex](x^{2} +6x^{2} ) + 5[/tex]
which equals to : [tex]7x^{2}[/tex] + 5
Hence, option C is correct.
To solve more questions on associative property , visit the link below -
https://brainly.com/question/20358404
#SPJ2