1. 


The graph of any equation in two variables is a straight line. 
2. 


The graph of any linear equation in two variables is a straight line. 
3. 


If f(x) = x^{2} + 3x, then f(1) = 4. 
4. 


If f(x) = 2x^{2} + 1, then f(3) = 37. 
5. 


If f(x) = 2, then f(1) is not defined. 
6. 


Every straight line has a slope. 
7. 


Every line is the graph of a linear equation in two unknowns. 
8. 


To find the equation of a line, all you need is a point and the slope. 
9. 


You need to know the yintercept to write down the equation of a line. 
10. 


The graph of a quadratic function f(x) = px^{2}+qx+r (with p nonzero) is always a parabola. 
11. 


In a linear cost function, the slope gives the cost of the first item. 
12. 


If displacement is a linear function of time, then the slope of the graph represents the velocity. 
13. 


If y is a linar function of x, then y increases by a fixed amount for each increase of one unit in y. 
14. 


If the weekly sales q of an item priced at $p are given by q = 3p + 40, then the weekly sales decrease by 3 items for every $1 increase in price. 
15. 


If the total weekly revenue for items priced at $p is given by the function R(p) = p^{2} + 100p, then the total weekly revenue will be $100 if we give the items away. 
16. 


A real valued function of a real variable is a rule that assigns a number to each specified number in a specified domain. 
17. 


Some functions assign two or more values to certain numbers in their domains. 
18. 


The regression line associated with two data points (with different xcoordinates) always passes through both points. 
19. 


The regression line associated with three data points (with different xcoordinates) always passes through at least two of those points. 
20. 


The regression line associated with a collection of more than two data points may pass through none of those points. 