18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
It would be negative six.
When you toss a coin 3 times here is what can happen:
H=heads
T= Tails
HHH TTT
<u>HHT</u> TTH
HTH THT
HTT THH
Since 8 things can happen and only one of them is what you want, the probability is 1/8
Another way to think about it is each toss has 1/2 of coming up as you want it to.
Three tosses are 1/2 x 1/2 x 1/2 which is 1/8
Answer:
- n = 5
- m = 12
- m= -14
- y =30
Step-by-step explanation:
1.
2.
3.
4.
Answer:
14 is a positive integer, then it belongs to the set of natural numbers.
1 and 5/9 are rational numbers. The second is already a fraction and the first one, 1, is a natural number, but all the natural numbers can be written as the result of a fraction. For example: 1=6/6.
About the last number, I don't know if it's written correctly. That should be pi maybe, that is 3.14159.... In that case it's an irrational number.
Irrational numbers are all those real numbers that are not rational.
In general you have that:
ℕ ⊂ ℤ ⊂ ℚ ⊂ ℝ
ℕ. Natural numbers. It's the "smallest" one.
ℤ. Integers. Made with positive and negative natural numbers. Includes the natural numbers then.
ℚ. Rational numbers. Everything that can be written as a fraction. Includes both ℕ and ℤ.
ℝ. Real numbers. Any kind of number, fraction or not.
