Answer: 210
Step-by-step explanation:
We know that the number of combinations of n things taken r at a time is given by :-
So, number of ways to select 3 plants out of 7 =
Also number of ways to arrange them in 3 positions = 3! = 6
Now , total number of arrangements with 1 plant in each spot = (number of ways to select 3 plants out of 7) x (number of ways to arrange them in 3 positions)
= 35 x 6
=210
Hence, required number of ways = 210
Answer:
Step-by-step explanation:
To figure this out imma show you a much easier way they is called a box method and i want you to creat a box and put on the top (4n-5) know on the other side where there is a red line on the paper put (4n-4) know this box method is simple all u have to do is multiply its simple and easy if you ever get stuck on something like this you can always use the box method.
The generic equation of the line is:
y-yo = m (x-xo)
Where, the slope is:
m = (y2-y1) / (x2-x1)
m = (1-4) / (2 - (- 1))
m = (1-4) / (2 - (- 1))
m = (- 3) / (3)
m = -1
We choose an ordered pair:
(xo, yo) = (- 1, 4)
Substituting values:
y-4 = -1 (x + 1)
Rewriting:
y = - x - 1 +4
y = -x + 3
Answer:
The equation of the line, in slope-intercept form, that contains the points (-1, 4) And (2,1) is:
y = -x + 3
Answer:the present age of the father is 45 years
Step-by-step explanation:
Let x represent the present age of the father.
Let y represent the present age of the son.
Let z represent the age of the daughter.
A father is 3 times as old as his son. This means that
x = 3y
his daughter is 3 years younger than the son. It means that
z = y - 3
The sum of their ages 3 years ago was 63. This means that
x - 3 + y - 3 + z - 3 = 63
x + y + z - 9 = 63 - - - - - - - - - - 1
Substituting x = 3y and z = y - 3 into equation 1, it becomes
3y + y + y - 3 - 9 = 63
5y - 12 = 63
5y = 63 + 12 = 75
y = 75/5 = 15
x = 3y = 3 × 15
x = 45
z = y - 3 = 15 - 3
z = 12
I believe it is a because I had a question just like that in 8th grade