Answer:
2x² + 23
Step-by-step explanation:
Distribute the -5 and combine like terms.
7x² + 3 - 5(x² - 4) =
= 7x² + 3 - 5x² + 20
= 2x² + 23
Answer:
52.7 g
Step-by-step explanation:
We are given;
- Initial mass of the element is 310 g
- Rate of decay 8.9% per minute
- Time for the decay 19 minutes
We are required to determine the amount of the element that will remain after 19 minutes.
We can use the formula;
New mass = Original mass × (1-r)^n
Where n is the time taken and r is the rate of decay.
Therefore;
Remaining mass = 310 g × (1-0.089)^19
= 52.748 g
= 52.7 g (to the nearest 10th)
Thus, the mass that will remain after 9 minutes will be 52.7 g
20%=0.20
20% of 18 is 18(0.2)=$3.6
$18-$3.6= $14.4
the discount price is $14.4
Answer:
A. -3(5x - 13)
Step-by-step explanation:
When you open the bracket
You have -3 x 5x -3(-13)
Negative negative gives you positive
Then it becomes
-15x + 39