Answer: -9 + 21 = t t = 12°C.
Step-by-step explanation: For this problem lets have t be equal to the original temperature in the beginning of the day. The equation -9 + 21 = t represents this situation because it states that if we add the degrees that dropped to the current degrees it will give us our original degrees.
Solve.
-9 + 21 = t (Simply add -9 + 21) -9 + 21 = (+12)
12 = t
So, the original degrees in the beginning of the day was 12°C.
Answer:
a³ + b³
Step-by-step explanation:
Given
(a + b)(a² - ab + b²)
Each term in the second factor is multiplied by each term in the first factor, that is
a(a² - ab + b²) + b(a² - ab + b²) ← distribute both parenthesis
= a³ - a²b + ab² + a²b - ab² + b³ ← collect like terms
= a³ + b³
Answer:
The weight of the block of ice after 1 day is of 4.81 pounds.
Step-by-step explanation:
Equation for exponential decay:
The equation that models an amount after t hours, subject to exponential decay, is given by:

In which A(0) is the initial amount and r is the decay rate, as a decimal.
A 10-pound block of ice melts at a rate of 3% per hour.
This means that 
So



Find the weight of the block of ice after 1 day.
One day has 24 hours, so this is A(24).

The weight of the block of ice after 1 day is of 4.81 pounds.