I did this equation and it’s A
Answer:
P=0.147
Step-by-step explanation:
As we know 80% of the trucks have good brakes. That means that probability the 1 randomly selected truck has good brakes is P(good brakes)=0.8 . So the probability that 1 randomly selected truck has bad brakes Q(bad brakes)=1-0.8-0.2
We have to find the probability, that at least 9 trucks from 16 have good brakes, however fewer than 12 trucks from 16 have good brakes. That actually means the the number of trucks with good brakes has to be 9, 10 or 11 trucks from 16.
We have to find the probability of each event (9, 10 or 11 trucks from 16 will pass the inspection) . To find the required probability 3 mentioned probabilitie have to be summarized.
So P(9/16 )= C16 9 * P(good brakes)^9*Q(bad brakes)^7
P(9/16 )= 16!/9!/7!*0.8^9*0.2^7= 11*13*5*16*0.8^9*0.2^7=approx 0.02
P(10/16)=16!/10!/6!*0.8^10*0.2^6=11*13*7*0.8^10*0.2^6=approx 0.007
P(11/16)=16!/11!/5!*0.8^11*0.2^5=13*21*16*0.8^11*0.2^5=approx 0.12
P(9≤x<12)=P(9/16)+P(10/16)+P(11/16)=0.02+0.007+0.12=0.147
Answer:
The intermediate step are;
1) Separate the constants from the terms in x² and x
2) Divide the equation by the coefficient of x²
3) Add the constants that makes the expression in x² and x a perfect square and factorize the expression
Step-by-step explanation:
The function given in the question is 6·x² + 48·x + 207 = 15
The intermediate steps in the to express the given function in the form (x + a)² = b are found as follows;
6·x² + 48·x + 207 = 15
We get
1) Subtract 207 from both sides gives 6·x² + 48·x = 15 - 207 = -192
6·x² + 48·x = -192
2) Dividing by 6 x² + 8·x = -32
3) Add the constant that completes the square to both sides
x² + 8·x + 16 = -32 +16 = -16
x² + 8·x + 16 = -16
4) Factorize (x + 4)² = -16
5) Compare (x + 4)² = -16 which is in the form (x + a)² = b
Multiplying both sides by 3, we get (3/9)*(2m-16)=(2m+4). Next, we multiply both sides by 9 and expand to get 6x-48=18m+36. Subtracting 6x and 36 from both sides, we get 12x=-48-36=-84. After that, we divide both sides by 12 to get m=-7
