Answer: 60mph
Step-by-step explanation:
500-300 = 200
200 = distance traveled in 2 hrs
100 = distance traveled every hour
100=2x+20, x being the slower train
80=2x
x=40
40+20 = 60, the speed of the faster train
Answer:
The probability that the average length of rods in a randomly selected bundle of steel rods is greater than 259 cm is 0.65173.
Step-by-step explanation:
We are given that a company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 259.2 cm and a standard deviation of 2.1 cm. For shipment, 17 steel rods are bundled together.
Let
= <u><em>the average length of rods in a randomly selected bundle of steel rods</em></u>
The z-score probability distribution for the sample mean is given by;
Z =
~ N(0,1)
where,
= population mean length of rods = 259.2 cm
= standard deviaton = 2.1 cm
n = sample of steel rods = 17
Now, the probability that the average length of rods in a randomly selected bundle of steel rods is greater than 259 cm is given by = P(
> 259 cm)
P(
> 259 cm) = P(
>
) = P(Z > -0.39) = P(Z < 0.39)
= <u>0.65173</u>
The above probability is calculated by looking at the value of x = 0.39 in the z table which has an area of 0.65173.
Answer:
x = 5/2 thì y = 35 và x = -5 thì y = 5
Step-by-step explanation:
thay y = 4x + 25 vào phương trình y = 2x ^ 2 + 9x ta có:
4x + 25 = 2x ^ 2 + 9x
⇒2x ^ 2 + 5x - 25 = 0
⇒ x = 5/2 và x = -5
thay x = 5/2 vào phương trình y = 4x + 25 ⇒ y = 4*(5/2) + 25 = 35
thay x = -5 vào phương trình y = 4x + 25 ⇒ y = 4*(-5) + 25 = 5
First number is a and second one is 2a+4
a(2a+4)=48
a(a+2)=24
a^2+2a-24=0
(a+6)(a-4)=0
the question says a is negative so a=-6 b=-8