Answer:
Leo is 11 years old
Step-by-step explanation:
* Lets explain how to solve the problem
- Alea is 5 times 3 less than leo's age
- Alea is 40 years old
- Assume that leo's age is x
* Lets change the words to equation
∵ Leo is x years old
∵ Alea is 5 times 3 less than Leo's age
- That means when we subtract 3 from Leo's age and multiply the
difference by 5 the result is Alea's age
∴ Alea's age = 5(x - 3)
- Multiply the two terms of the bracket by 5
∴ Alea's age = 5x - 15
∵ Alea is 40 years old
- Equate the expression of Alea's age by her age
∴ 5x - 15 = 40 ⇒ the equation to find Leo's age
- Add 15 to both sides
∴ 5x = 55
- Divide both sides by 5
∴ x = 11 ⇒ the solution of the equation
∵ x represents the Leo's age
∵ x = 11
∴ Leo is 11 years old
X = 1st number
y = 2nd number
x + y = 200
x : y = 4 : 6
ok! let's substitute numbers!
4 * 10 : 6 * 10
40 : 60
40 + 60 = 200
100 ≠ 200
Too small!
That is exactly two times smaller than 200 so let's try 2 times greater than multiplying by 10
4 * 20 : 6 * 20
80 : 120
80 + 120 = 200
200 = 200
Now it says to find the larger number. Which is y.
x :y = 4 : 6 = 80 : 120
so, y is 120
y = 120
Answer : y = 120. The larger number is 120.
DB/dt = k*B
dB/(kB) = dt
Integrating both sides:
1/k*ln|B| = t + C
B = C*e^(kt)
At time t = 0, B = 4000 and at time t = 3 (3 hours past 9 AM), B = 4500
4000 = C
4500 = 4000*e^(3k) => k = 1/3*ln(9/8)
At time t = 15 (Midnight), B = 4000*e^(1/3*ln(9/8)*15) = 4000*(9/8)^5 = 7208 bacteria
Answer:
a) At what time does Bethan arrive home from school?
The answer would be C) 15:30
b) What distance does Siobhan travel each day when going to school and back?
The answer would be D) 16km
Step-by-step explanation:
Answer:
-8
Step-by-step explanation:
All you have to do to solve this equation is plug "-3" into the equation where you see "x"
