Answer:
See below.
Step-by-step explanation:
Given :-
x² + bx + c = 0 if x₁ + x₂ = -b and x₁x₂ = c
Solving :-
a) x₁ = 1/2 and x₂ = -3/4
=> x² + -(1/2 + -3/4)x + 1/2(-3/4)
=> x² + -(-1/4)x + (-3/8)
=> x² + 1/4x - 3/8
=> 8x² + 2x - 3 = 0
b) x₁ = 1 + √5 and x₂ = 1 - √5
=> x² + -(1 + √5 + 1 - √5)x + (1 + √5)(1 - √5)
=> x² - 2x + 1 - 5
=> x² - 2x - 4 = 0
Remember that x/4 and 1/4*x is the same thing.
1/4*52 is therefore the same as 52/4. Fractions represent division, so 52 divided by 4 is also correct.
0.25*x is the same as 1/4*x because 1/4=0.25
4% of 52 is incorrect because the decimal form of 4% is 0.04, which is not the same as 0.25
Final answer: B
Answer:
Time(min)
2
6
8
15
Distance(km)
6
18
24
45
Step-by-step explanation:
the time is 1/3rd of the distance. it's a 1:3 ratio
Answer:
We accept H₀ with the information we have, we can say level of ozone is under the major limit
Step-by-step explanation:
Normal Distribution
population mean = μ₀ = 7.5 ppm
Sample size n = 16 df = n - 1 df = 15
Sample mean = μ = 7.8 ppm
Sample standard deviation = s = 0.8
We want to find out if ozono level, is above normal level that is bigger than 7.5
1.- Hypothesis Test
null hypothesis H₀ μ₀ = 7.5
alternative hypothesis Hₐ μ₀ > 7.5
2.-Significance level α = 0.01 we will develop one tail-test (right)
then for df = 15 and α = 0,01 from t -student table we get
t(c) = 2.624
3.-Compute t(s)
t(s) = ( μ - μ₀ ) / s /√n ⇒ t(s) = ( 7.8 - 7.5 )*4/0.8
t(s) = 0.3*4/0.8
t(s) = 1.5
4.-Compare t(s) and t(c)
t(s) < t(c) 1.5 < 2.64
Then t(s) is inside the acceptance region. We accept H₀
