Fill in the blanks to make the following statements true:

[13 + (– 12)] + (............) = 13 + [(–12) + (–7)]

Dear Student

Let us assume the missing integer be x,
Then,
= [13 + (–12)] + (x) = 13 + [(–12) + (–7)]
= [13–12] + (x) = 13 + [–12–7]
= [1] + (x) = 13 + [-19]
= 1 + (x) = 13–19
= 1 + (x) = -6
By sending 1 from LHS to RHS it becomes -1,
= x = -6–1
= x = -7
Now substitute the x value in the blank place,
= [13 + (–12)] + (-7)
= 13 + [(–12) + (–7)]... [This equation is in the form ofAssociative property of Addition]

Thanks