To get roots of 13 and -3 the simplified equation will have to look like this.
(X-13)(X+3)=0
So if we multiply this out with foil method we get this:
X^2 -10X -39
So the answer is A
In a positive correlation, both variables increase together. An example of this is a company's profit's relationship with its sales. The greater the sales, the greater the profit.
A negative correlation is where one variable decreases with increase in the other. An example is the time taken to reach somewhere and the speed traveled at. The faster you move, the less the time.
No correlation means the two variables are not related. An example of this is as you get older, it does not mean you will get better grades.
We check with each options
'Or' represents the intersection of two graphs
'And' represents two separate graphs'
We have two separate shaded part in the given graph
So we ignore the options that has 'and' in between
LEts check first and second option
Simplify the first part and second part
multiply both sides by 2 .
x < 2 or 4x - 2 > = 26
solve 4x-2 > = 26
add 2 on both sides and then divide both sides by 4
4x >= 28
x >= 7
So solution is x<2 or x>=7 . that is the graph on number line
Lets check with second option
3x-3<3 or 2x+8>=22
add 3 on both sides
3x < 6
divide both sides by 3
so x< 2
2x+8>=22
subtract 8 on both sides
2x >= 30
divide both sides by 2
x >= 15
x<2 or x>=15 that does not satisfies the graph
So option A is correct
v₀ = initial velocity of the freight train while it approach a road crossing = 16 km/h = 16 (5/18) m/s = 4.44 m/s
v = final velocity of the freight train after it crosses a road crossing = 65 km/h = 65 x 5/18 m/s = 18.06 m/s
t = time to do so = 10 min = 10 x 60 sec = 600 sec
acceleration is given as
a = (v - v₀ )/t
a = (18.06 - 4.44)/(600)
a = 0.023 m/s²
a = 294