Answer:
9 years old.
Step-by-step explanation:
Since the ages of all of these students are being represented in relation to the middle student's age then we can create formulas for each student and then apply them to the formula for the sum of their ages and solve for the middle child's age (M) like so... (oldest child's age is represented by variable O and youngest child's age is represented by variable Y)
O = M + 6
Y = M - 3
30 = (M+6) + M + (M-3) ... combine like terms
30 = 3M + 3 ... subtract 3 from both sides
27 = 3M ... divide both sides by 3
9 = M
Now we know that the middle child is 9 years old.
Answer: -11 degrees Celsius
Step-by-step explanation:
4:00 am = -16 degrees
You know that 4:00am is four hours after midnight and you know that the temperature decreases by 1.75 degrees every hour so during that time it has dropped by:
1.75x4=7 degrees
Because it is -16 at 4:00am, you know it was 7 degrees higher at midnight
-16+7=-11
It was -11 degrees at midnight
Answer: 32
Step-by-step explanation: the big number is 64 and the smallest number is 32. 64-32=32
Area of rhombus = 
where x and y are diagonals.
Given length of one diagonal is 4.5 dm
So, let x= 4.5dm
1 dm = 10 cm
4.5dm= 45cm
area =
so, 
y = 24 cm
The two diagonals are x= 45cm and y = 24cm
Since diagonals bisect each other, we get 22.5cm and 12cm
Using right triangle formula
r = 10.588cm
Distance of center to the side = 
= 5.294 cm
Answer:
f(4) =0 because 4>0
f(-2) =-2 coz -2 lies between 0 and -3
f(-5) =2/-5
