Answer:
<h2>6</h2>
Step-by-step explanation:

Substitute 2 for z in the given equation

Follow the PEMDAS order of operations

The radius is 9. U just need to do the circumference divided by 2
P(the students she selects are both boys)=7/12×5/10=35/120=7/24
Answer:
Step-by-step explanation:
a) Here we have:
"In Family A, the youngest child is 7 years younger than the oldest, who is 18"
Let's define:
Y = age of the youngest child.
O = age of the oldest child.
Then we know that:
Y = O - 7
O = 18
Then we can replace the second equation into the first one:
Y = 18 - 7 = 11.
b) Here we have:
"In Family B, the middle child is 5 years older than the youngest child."
Let's define:
Y = age of the youngest child.
M = age of the middle child.
Here we have only one equation:
M = Y + 5.