0.8 is 20% of 4. This is because 20% of something occurs when something is divided by 5, since it is 1/5 of 100. You multiply 0.8*5, and you get 4.
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Explanation:</h2><h2>
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Here you haven't provided any function, so I'll assume this one:

This is a quadratic function whose graph represents a parabola. Any parabola has its vertex at the point:

Therefore:

Therefore, the vertex is:

Answer:The equation of any straight line, called a linear equation, can be written as: y = mx + b, where m is the slope of the line and b is the y-intercept. The y-intercept of this line is the value of y at the point where the line crosses the y axis.
Step-by-step explanation:
Answer:
240 minutes
Step-by-step explanation:
If it's 40 minutes for just 5 papers, we need to figure how many minutes it would take to grade just 1. So you have to divide 40 by 5 which is 8. Then 8 time 30 which is 240.
Answer:
The width is: 
The length is 
Step-by-step explanation:
The given rectangle has area given algebraically by the function:

The width of the rectangle is the greatest common factor of
,
and 
That is the width is: 
We now divide the area by the width to obtain the length of the rectangle:

This simplifies to:

