Answer:
0.0656
Step-by-step explanation:
For each message, we have these following probabilities:
90% probability it is spam.
10% probability it is legitimate.
Compute the probability that the first legitimate e-mail she finds is the fifth message she checks:
The first four all spam, each with a 90% probability.
The fifth legitimate, with a 10% probability.
Answer: 7.25 gallons
Step-by-step explanation:
Convert 13¹/₂ to a whole number with a decimal:
= 1/2 = 0.5
= 13.5 gallons of gas
If the gas reduces by 6.25 gallons, the amount of gas remaining will be:
= Starting amount - Amount reduced by
= 13.5 - 6.25
= 7.25 gallons
Answer:
The value of x and y that satisfy the equations is x = 2 and y = 1
Step-by-step explanation:
Given
2.5(x−3y)−3=−3x+0.5
3(x+6y)+4=9y+19
Required.
Find x and y
We start by opening all brackets
2.5(x−3y)−3=−3x+0.5 becomes
2.5x - 7.5y - 3 = -3x + 0.5
Collect like terms
2.5x + 3x - 7.5y = 3 + 0.5
5.5x - 7.5y = 3.5 ---- Equation 1
In similar vein, 3(x+6y)+4=9y+19 becomes
3x + 18y + 4 = 9y + 19
Collect like terms
3x + 18y - 9y = 19 - 4
3x + 9y = 15
Multiply through by ⅓
⅓ * 3x + ⅓ * 9y = ⅓ * 15
x + 3y = 5
Make x the subject of formula
x = 5 - 3y
Substitute 5 - 3y for x in equation 1
5.5(5 - 3y) - 7.5y = 3.5
27.5 - 16.5y - 7.5y = 3.5
27.5 - 24y = 3.5
Collect like terms
-24y = 3.5 - 27.5
-24y = -24
Divide through by - 24
y = 1
Recall that x = 5 - 3y.
Substitute 1 for y in this equation
x = 5 - 3(1)
x = 5 - 3
x = 2
Hence, x = 2 and y = 1
Answer:
±3i
Step-by-step explanation:
Given the value ±√-9, we are to express the value using the imaginary number 'I'
±√-9 = ±√9×-1
= ±√9 × √-1
In complex number, √-1 = i
The expression becomes;
±√9 = ±3 × i
±√9 = ±3i
Hence the value in simplified form is ±3i
