Answer: 3 years
Because:
1 year=1050
2years=525
3years=262.5
(4x+6)(2x-5)
= 8x^2 - 20x + 12x - 30
= 8x^2 - 8x - 30
The formula can be written in the form ...
... T = (original temperature) + x·(change in temperature each minute)
The problem statement gives you the original temperature (21 °C) and tells you the temperature after 12 minutes. You have to use that information to figure out the change in temperature each minute.
The change in temperature in 12 minutes is (75 °C) - (21 °C) = 54 °C. That is the change in 12 minutes, so the change in 1 minute will be 1/12 of that:
... 54/12 = 4.5
Using this value in the equation for T, we have
... T = 21 + 4.5x
Answer:
First, distribute the -2 to each value in the parentheses.
-2x + 4 = 10
(The 4 is positive because a negative multiplied by a negative is a positive)
Then, subtract 4 from both sides to get rid of it.
-2x = 6
Divide by -2 to get x by itself
x = -3
A list of positive whole numbers less than 8 are 7, 6, 5, 4, 3, 2, and 1.
There's your answer
Sam
