Answer:
x = -3, 6
Step-by-step explanation:
First, add 18 to both sides
x² - 3x - 18 = 0
+ 18 + 18
x² - 3x = 18
Add 9/4 to both sides because that is the square of half of -3
x² - 3x + 9/4 = 18 + 9/4
Multiply both sides by 4 to get rid of the fractions
(x² - 3x + 9/4 = 18 + 9/4)4
4x² - 12x + 9 = 72 + 9 = 81
Factor the left side of the equation
(2x - 3)² = 81
√(2x - 3)² = √81
Because of the square root, this will result in a positive number and a negative number
2x - 3 = 9
2x - 3 = -9
For both equations, add 3 to both sides then divide by 2
2x - 3 = 9
+ 3 +3
2x = 12
2x/2 = 12/2
x = 6
2x - 3 = -9
+ 3 + 3
2x = -6
x = -3
Answer:
a) £15.40 b) 260g c) 22p d) 121mm
Step-by-step explanation:
To work out a 10% increase, times the number by 1.10 or 1.1!
Hope this helped :)
Answer:
The standard deviation of the number of runs required is 2447.26
Step-by-step explanation:
For each run, there are only two possible outcomes. Either the program fails, or it does not. The probability of the computer failing during a run is independent of other runs. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The standard deviation for the expected number of trials for r sucesses is:
A computer program has a bug that causes it to fail once in every thousand runs, on average.
This means that 
In an effort to find the bug, independent runs of the program will be made until the program has failed six times. What is the standard deviation of the number of runs required?
This means that r = 6. So
The standard deviation of the number of runs required is 2447.26
Answer:
$5.75
Step-by-step explanation:
Joshua paid $9.10 for a bag and has $16.25 left
Now let's find out how much Joshua had before spending on a bag. To do this, we simply sum up the cost of the bag and how much Joshua had lefyt
9.10 + 16.25
=$25.35
Since Joshua and Shopping had the same amount, Shuping also had $25.35
To get the cost of the pen, we subtract the amount Shuping had left after purchasing the pen
This gives;
25.35 - 19.60
=$5.75
Object A. You can use the area theorem to solve. Just do base x height to get the area of a shape.
