The ages are consecutive even numbers.
The youngest child is (x+3) years old.
Every even number is 2 more than the one before it.
So the three ages are
(x + 3), (x + 5), and (x + 7).
Their sum is x+3 + x+5 + x+7 = 3x + 15
But we're told that their sum is 42, so we can write
3x + 15 = 42 <== the equation
Subtract 15 from each side: 3x = 27
Divide each side by 3 : x = 9 <== the solution
So the three ages are 12, 14, and 16.
The oldest child is 16 years old.
Plotting the data to get the line of best fit, it is:
y<span> = 0.087</span>x<span> + 0.587
substitute x=2030-1980=50,
y = $4.94 is the price in 2030</span>
Answer: It will take 7 stages for all 19,530 families to be called.
In the first stage, only 5 families are called.
In the second stage, we would have 5 x 5 = 25 families being called.
In the third stage, we would have 5 x 5 x 5 = 125 families being called.
We can use exponents to finish the list and see when our goal is reached.
4th stage: 5^4 = 625
5th stage: 5^5 = 3125
6th stage: 5^6 = 15625
7th stage: 5^7 = 78,125
