Let the numbers be x and y. Then xy = -30 and x+y = -3.
Solve xy = -30 for y: y = -30/x
subst. -30/x for y in x+y= -3: x - 30/x = -3
Multiply all 3 terms by x: x^2 - 30 = -3x, so x^2 + 3x - 10 = 0
Solve this quadratic equation for x. x: {-5, 2}
If x = -5, then x+y = -3 becomes -5 + y = -3, and y = 2.
You should check to determine whether x=2 is also correct. If it is, what is the corresponding y value?
Answer: 24
Step-by-step explanation:
m - 15 + 15 = 9 + 15
m = 24
See picture for answer and solution steps.
Answer: B) 4 & 1/6
Nice work on getting the correct answer.
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Explanation:
x is opposite the marked acute angle
5 is opposite the corresponding acute angle
So x and 5 are proportional to each other. We can form the ratio x/5
Similarly, 10 and 12 are proportional to one another. We can form the ratio 10/12.
Set those ratios equal to each other and solve for x
x/5 = 10/12
12x = 5*10 ... cross multiply
12x = 50
x = 50/12 ...... divide both sides by 12
x = (25*2)/(6*2)
x = 25/6
x = (24+1)/6
x = 24/6 + 1/6
x = 4 + 1/6
x = 4 & 1/6 which shows why <u>choice B</u> is the answer.
Side note: 25/6 = 4.167 approximately
Answer:
And if we solve for a we got
Step-by-step explanation:
Let X the random variable that represent the lenght time it takes to find a parking space at 9AM of a population, and for this case we know the distribution for X is given by:
Where
and
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
As we can see on the figure attached the z value that satisfy the condition with 0.7 of the area on the left and 0.3 of the area on the right it's z=0.524
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got