Graphs of Straight Lines
5.2 Graphs of Straight Lines•Linear equations in two variables ( y = mx + b, Ax + By = C)
o The graph of a linear equation is a straight line
o A solution of a linear equation is an ordered pair (x, y) that makes the equation true
Ex. a) Is (0, -1) a solution of y = 2x –1?
b) Is (2, -2) a solution of y = 3x + 8?
Ex. Find the ordered pair solution of y = -3x that corresponds to x = -1
Ex. Find the ordered-pair solution of that corresponds to x = -4
•To graph a linear equation, find two (or more) ordered-pair solutions by choosing any value for x and finding the corresponding value of y.
•x and y-intercepts ( x, 0), (0, y). To find the x-intercept you let y = 0, and to find the yintercept you let x = 0• Solve Ax + By = C for y
• Graphs and equations of vertical and horizontal lines
|a) y = x – 2
||b) y = -3x + 1
d) –2x + y = 1
|e) x – 4y = 8
||f) y = -3 ( Horizontal line)
|g) x = 1 ( Vertical line)
|h) x + 2y = 6
Ex. Solve 2x +3y = 9 for y: ___________________________________________
HW page 270 # 3 – 23 every other odd, 29-57 every other odd, 63–113 every other odd