Which expression is equivalent to a + (c + 7)?
7 a c
a minus (c + 7)
(c + 7) minus a
(a + c) + 7

(a+c)+7

Step-by-step explanation:

this is called the Associative Property

(x+y)+z=x+(y+z)

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

copy and paste, put it in google