Answer:
case a)
----> open up
case b)
----> open down
case c)
----> open left
case d)
----> open right
Step-by-step explanation:
we know that
1) The general equation of a vertical parabola is equal to

where
a is a coefficient
(h,k) is the vertex
If a>0 ----> the parabola open upward and the vertex is a minimum
If a<0 ----> the parabola open downward and the vertex is a maximum
2) The general equation of a horizontal parabola is equal to

where
a is a coefficient
(h,k) is the vertex
If a>0 ----> the parabola open to the right
If a<0 ----> the parabola open to the left
Verify each case
case a) we have

so


so

therefore
The parabola open up
case b) we have

so



therefore
The parabola open down
case c) we have

so



therefore
The parabola open to the left
case d) we have

so



therefore
The parabola open to the right
80% is the same as 4/5, so 4/5 of the class= 20. That means that if there was a picture, 4 parts would be shaded, and 1 would not. 1/4 of 20 is 5, so 1 part= 5 people. 5 x 5 = 25. 25 is the answer. :)
Answer: 8 weeks
Step-by-step explanation:
Using a calculator, 1200/180 = 6.67 approximately
If you use long division, then you'll get what you see in the diagram below
The 6's go on forever after the decimal point, but if you round to two decimal places, then you'll get that approximate value of 6.67
---------------
If you want a remainder, then 1200/180 = 6 remainder 120
You can think of it like you having 1200 cookies and 180 friends. Each friend will get 6 whole cookies and there will be 120 left over as the remainder.
Answer:
(x - 4)² - 11
Step-by-step explanation:
Given
x² - 8x + 5
To obtain the required form use the method of completing the square.
add/subtract ( half the coefficient of the x- term)² to x² - 8x
= x² + 2(- 4)x + 16 - 16 + 5
= (x - 4)² - 11