The answer should be the directrix because k represents the y-value of the vertex, and for this questions the parabola is probably facing upward, so the directrix is under the vertex.
There are 7 math books, 9 science books and 5 literature books. Student has to select 2 books from each set.
This is a combination problem.
Number of ways to select 2 math books from 7 books = 7C2 = 21
Number of ways to select 2 science books from 9 books = 9C2 = 36
Number of ways to select 2 literature books from 5 books = 5C2 = 10
Total number of ways to select 2 books from each set = 21 x 36 x 10 = 7560 ways.
So there are 7560 ways to select 2 books from each set of seven math books, nine science books, and five literature books
Let's call 'it' x. 1/2 is equal to one third of x, so we could say that 1/3x = 1/2
Now we just have a simple equation to solve:
1/3x = 1/2
x = (1/2) / (1/3)
Dividing by a rational number (such as 1/3, which is expressed in fraction form) is the same as multiplying by its reciprocal (the reciprocal of a fraction is itself when the numerator and denominator have been swapped). Therefore
x = (1/2) / (1/3) = (1/2) * 3 = 3/2 = 1.5
To check this answer, test the statement. Half is a third of x, where x=1.5:
1.5 / 3 = 0.5 = 1/2
Point-slope equation=y+1=5(x+2)
slope intercept form=5x+9
Answer:
Step-by-step explanation:
![\textsf{x=1/2[(4x+5)-50]}](https://tex.z-dn.net/?f=%5Ctextsf%7Bx%3D1%2F2%5B%284x%2B5%29-50%5D%7D)
