When solving an equation, Bianca's first step is shown below. Which property justifies Bianca's first step? Original Equation:
3
+
(
2
+
x
)
=
3+(2+x)=

5
5
First Step:
First Step:
(
3
+
2
)
+
x
=
(3+2)+x=

5
5

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.