Answer:
Step-by-step explanation:
The vertex and focus are horizon aligned, so the parabola is horizontal and the directrix is a vertical line.
The vertex is halfway between focus and directrix. Directrix: x = -4
It is easier to understand the problem if you create a number based on the criteria and then perform the computations. I am going to choose: 111 22 33 4
There are 10 options for the first "1" and only 1 option for the other two 1's
There are 9 remaining options for the first "2" and only 1 option for the other 2
There are 8 remaining options for the first "3" and only 1 option for the other 3
There are 7 remaining options for the "4"
10 x 1 x 1 x 9 x 1 x 8 x 1 x 7
10 x 9 x 8 x 7 = 5,040
Answer: 5,040
Answer:
x = -11
Step-by-step explanation:
2x + 23 + 9 = x + 21
Combine common factors
2x + 32 = x + 21
Subtract x from both sides
x + 32 = 21
Subtract 32 from both sides
x = -11
Answer:
B
Step-by-step explanation:
A. these simply to 21 + 7x and 21 + 3x
- this one is incorrect because the 7x and 3x are different
B. these simplify to 10 + x and 10 + x
- this is the correct one since they are exactly the same
C. these simplify to 21x and 7x + 21
- these two are not the same because one expression has only a number with a variable but the other one has a number with a variable <em>and </em>another number
D. these simplify to
and 
- in subtraction, the order of the 3 and the x matters, so the equations are not the same
- example: 6 - 4 = 2 but 4 - 6 = -2