<u>Answer:</u>
Heather = 18 messages
Brian = 25 messages
Austin = 54 messages
<u>Step-by-step explanation:</u>
We know that Heather, Brian, and Austin sent a total of 97 messages.
Assuming the number of messages sent by Brian as x, we can say that Heather sent x-7 messages (7 fewer messages than Brian) and Austin sent 3(x-7) messages (3 times as many as Heather).

So Brian sent (x) messages = 25 messages,
Heather sent (x-7) messages = 25 - 7 = 18 messages; and
Austin sent 3(x-7) messages = 3(25-7) = 54 messages
Answer:
the answer is a bc the 1 in this makes sense
Step-by-step explanation:
thats is the best answer i think
The balanced chemical reaction is written as:
C + O2 = CO2
We are given the amounts of the reactants to be used in the reaction. We use these values for calculations. Since there is oxygen that is left in the reaction then the limiting reactant would be carbon. We calculate as follows:
16.8 g C ( 1 mol / 12.01 g) ( 1 mol CO2 / 1 mol C ) ( 44.01 g / 1 mol) = 61.56 g CO2 produced
Your answer is C) 2a² + 2b²
To find this we can just expand the brackets of (a - b)² and (a + b)², and then combine like terms:
(a - b)² = (a - b)(a - b) = a² - 2ab + b²
(a + b)² = (a + b)(a + b) = a² + 2ab + b²
Then when you combine like terms, you get (a² + a²) + (-2ab + 2ab) + (b² + b²), so the ab terms cancel out and you get left with 2a² + 2b².
I hope this helps!