-16t^2+400=0
16t^2=400
take square root on both sides.

4t=20
t=20/4
t=5
Answer:
11 dimes, 17 nickels
Step-by-step explanation:
d + n = 28, put one variable by itself on a side, d = 28 - n
.10d + .05n = 1.95
Sub the first equation into the second
.10(28 - n) + .05n = 1.95
2.8 - .10n + .05n = 1.95
2.8 - .05n = 1.95
-.05n = -0.85
n = 17 nickels
d + 17 = 28
d = 11 11 dimes
Answer:
61 Students.
Step-by-step explanation:
So you need to find 20% of 305. You can do this by dividing by 5.
305 divided by 5 equals 61.
If you have questions, ask please :)
Answer:
n = 20 or n = -2
Step-by-step explanation:
Solve for n over the real numbers:
n^2 = 18 n + 40
Subtract 18 n + 40 from both sides:
n^2 - 18 n - 40 = 0
The left hand side factors into a product with two terms:
(n - 20) (n + 2) = 0
Split into two equations:
n - 20 = 0 or n + 2 = 0
Add 20 to both sides:
n = 20 or n + 2 = 0
Subtract 2 from both sides:
Answer: n = 20 or n = -2
Given the numbers above and those numbers only the mean would be 1.8