has a parabola as its graph; the height of the baseball relative to the time elapsed can be modelled by this parabola. The height of the baseball when it reaches its peak corresponds to the vertex of the parabola. The first coordinate of the vertex, or , is equal to , where, here,

 and .

Therefore, the time coordinate of the vertex is 

Of the given responses, 3 seconds comes closest.

When the ball hits the ground, the height is 0, so set  and solve for :

Either  or .

If , then . Since time cannot be negative, we throw this out.

If , then  - this is the answer we accept. 

The ball hits the ground in 6 seconds.

 has a parabola as its graph; the height of the baseball relative to the time elapsed can be modelled by this parabola. The height of the baseball when it reaches its peak corresponds to the vertex of the parabola. The first coordinate of the vertex, or , is equal to , where, here,

The time elapsed after the baseball reaches its peak is

 seconds.

The height at that time is 

 feet.

The closest of the given responses is 200 feet.

The data given can be written in the form of two ordered pairs , with  the number of the year and  the number of catfish - these pairs are  and .

Setting  in the slope formula, the line through these two points has slope

Using the point-slope formula with the first point, the line that models the catfish population is

Let  be the speed of the river current. 

The speed of the boat going downstream is , the sum of the speed of the boat in still water and the speed of the river current. Since rate is distance divided by time, 

To get the speed of the boat going upstream, subtract the speed of the current from that of the boat in still water:  miles per hour.

Since rate multiplied by time is equal to distance, we have:

 hours,

making the correct choice 11 hours.

You must first set up a revenue equation where  represents the number of bunches of apples sold and  represents the number of watermelons sold.  

This would give us the equation 

.  

The problem gives us both  and  and when we plug those values in we get 

or

.

Now you must get  by itself.  

First, subtract  from both sides leaving .  

Then divide both sides by  to get your answer .

To solve this algebraic word problem, first set up an equation:

The variable  represents the amount of people in the group.

Add 

Isolate the variable by adding 8 to both sides of the equation:

Check to make sure that the two conditions of the problem have been met.

Condition one: The two numbers added together must equal 60.

Condition two. One of the numbers is eight less than the other.

Because these two conditions have been met, there are  people in one group and  people in the second group.

The formula for computing the area of a rectangle is Area = l x w, where l = length and w = width.

In this algebraic word problem, let the variable  represent the length and  will represent the width of the rectangle.

Write an equation:

Distribute the variable  to what is inside the parentheses:

Set that expression equal to zero by subtracting 36 from both sides:

Factor using the FOIL Method:

Set each equal to zero to find the values of x that make this expression true:

There are two possible values for ;  and 

Because a dimension cannot be a negative integer, reject  Therefore . This is the measurement of the length of the rectangle.

 represents the width of the rectangle.

Now check to see if the two conditions are met.

Condition 1: Area = length x width

Condition 2: The width is 5cm less than the length.

Therefore  is the length and  is the width of this rectangle.