<span><span> <span>Akar akar persamaan kuadrat 2x² - 3x -1 = 0 adalah x1 dan x2. Persamaan kuadrat baru yang akar akarnya satu lebih kecil dari dua kali akar akar persamaan kuadrat di atas adalah ........</span></span><span><span><span>A.x² - x - 4 = 0</span><span>B.x² + 5x - 4 = 0</span><span>C.x² - x + 4 = 0</span></span><span><span>D.x² + x + 4 = 0</span><span>E.x² - 5x - 4 = 0</span></span></span><span>Jawaban : A
Penyelesaian :
Akar-akar persamaan lama : x1 dan x2
Akar-akar persamaan baru : xA dan xB
xA = 2x1 - 1
xB = 2x2 - 1
xA + xB = (2x1 - 1) + (2x2 - 1)
= 2 (x1 + x2) - 2
= 2 () - 2
= 3 - 2
xA + xB = 1
xA . xB = (2x1 - 1) (2x2 - 1)
= 4 x1.x2 - 2(x1 + x2) + 1
= 4.(-) - 2() + 1
= -2 - 3 + 1
xA . xB = -4
Jadi persamaan kuadrat baru : x² - (xA + xB)x + xA . xB = 0
x² - x - 4 = 0
</span></span>
Answer: x= 55 because 60 + 65 =125 and 180 - 125 = 55
Step-by-step explanation:
The sum of three angles in any triangle is 180. Therefore you add the two angles that you have and use that number to subtract it by 180. Then you will have your answer. Also you can get the answer to y by subtracting the value of x from 180.
I think $8.50 is how much 5 pounds is
Answer:
The game’s expected value of points earned for a turn is 71.
Step-by-step explanation:
Here we know that:
Points Frequency
50 55
75 32
150 13
Here points earned is a random variable.
We need to find its expected value,
Finding Expected value:
Expected value of a random variable is its mean value. So we will first find the mean value of points earned per turn from the table we are given.
Total number of turns = sum of frequencies
= 55 + 32 + 14 = 100
Total points earned = 50(55) + 75(32) + 150(13)
= 7100
Expected value of points earned for a turn = Mean value of points
= Total points/no. of turns
= 7100/100
= 71
Powers distribute over multiplications:
So, you have
Now, is simply 9.
As for , we have to use the rule
to get
So, the final answer is