Vocabulary
Parallel & Perpendicular Lines
Direct & Inverse Variation
Direct & Inverse Variation Word Problems
Graphing Inequalities
100
What is the general equation for direct variation?
y = kx
100
What is the difference between parallel lines and perpendicular lines?
Parallel lines never intersect, but perpendicular lines intersect at a 90 degree angle.
100
Describe the difference between direct and inverse variations.
Direct variation - y is directly proportional to x. i.e. y = kx Inverse variation - y is inversely proportional to x. i.e. xy =k
100
y is directly proportional to x. If y = 30 when x = 6, express an equation to include the value of the constant to represent the given situation.
y = 5x
100
Please list the four steps towards graphing an inequality.
1. Ensure y is by itself. 2. Plot two points on graph by plotting y - int and using rise over run methods. 3. Draw solid or dashed line. 4. Shade the appropriate region.
200
What is the general equation for inverse variation?
xy = k
200
What is the slope of a line that is parallel to the line y = -3x +1?
-3
200
y varies directly with x. y = -7 when x = -14. Find y when x = 20.
y = 10
200
Which of the following equations represent a direct variation equation. y = (1/2)x, y = 2/x, y = x + 2, y/x = 3
y = (1/2)x and y/x = 3
200
Graph the linear inequality y <= (3/5)x - 2
The exact value of y could be either on the line or above the line.
300
What is the slope intercept formula?
y = mx + b
300
What is the slope of a line that is perpendicular to the line y = 7x?
-1/7
300
y varies inversely with x. If y = 1.6 when x = 0.5, find x when y = 3.2.
x = 0.25
300
The total cost of filling up your car with gas varies directly with the number of gallons of gasoline you are purchasing. If a gallon of gas cost $2.25, then how many gallons could you purchase for $18?
x = 8 gallons
300
Graph the following linear inequality 6x - 2y < 4.
The exact y value could be anywhere above the line.
400
What is the point slope formula?
y - y1 = m(x - x1)
400
Write the equation of a line that is parallel to 8x - 2y = 10 and passes through the point (-1, 2).
y = 4x +6
400
Find an equation that relates x and y inversely, and y = 10 when x = 5.
xy = 50
400
In outer space, the distance that an object travels varies directly with the amount of time that it travels. If an asteroid travels 3000 miles in 6 hours, what is the constant of variation?
k = 500
400
Graph the inequality, y <= 3 - 2x. Then determine which of these ordered pairs could contain the possible value for y. (0, 4), (-1, 3), (6, -8), (-4, 5)
The exact value of y could be any y value at or beneath the line. The ordered pairs (-1,3), (-4, 5) both contain possible y values that could represent that value.
500
What does the k value represent? What is the meaning behind it?
It represents the constant of variation.
500
Write the equation of a line that is perpendicular to 8x - 2y = 10 and passes through the point (-4, -3).
y = (-1/4)x - 4
500
If L is a constant, then what type of variation does v = L/T represent?
Inverse
500
The time it takes to travel a certain distance varies inversely as the rate r at which you travel. The table (5, 50) , (10, 25), (20, 12.5) can be used to represent a person driving 250 miles. Please state the equation corresponding to this table. Be sure to include the value of k in your equation
rt = 250
500
Graph the inequality, 3x + 4y < 7. Then determine which of these ordered pairs could contain the possible value for y. (1, 1), (2, -1), (-1, 1), (-2, 4)
The exact value of y could be any y value beneath the line. The ordered pairs (2, -1), (-1, 1) both contain possible y values that could represent that value.
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