Warm Ups (Wednesday 4/22) Jerry wants to ride in a hot air balloon. It costs $180 dollars to rent the balloon and an additional $30 dollars for each hour the balloon is in the air. Jerry has $250 dollars. Will he be able to afford a two hour balloon ride?

Slope intercept form is a great way to write a linear equation if we know the slope and the y-intercept! y = mx + b y-intercept slope But what if we don’t know the y-intercept?!

Point Slope Form! It’s okay if we don’t know the y-intercept. All you need is: 1.the slope, m 2.a point on the line, (x 1, y 1 ) Then, put them in the Point Slope Equation: y – y 1 = m(x – x 1 )

Example 1 Write an equation in point slope form for a line with a slope of 4 that includes the point (3, -2). y – y 1 = m(x – x 1 )

Example 2: Write an equation in point slope form for a line with a slope of -⅔ that includes the point (-5, 4). Example 3: Write an equation in point slope form for a line with a slope of -2 that includes the point (7, 6). y – y 1 = m(x – x 1 )

Graphing In Point Slope Form 1)Use the formula to find (x 1, y 1 ). Then, plot the coordinate. 2)Use m, the slope, to make your line.m = rise run y – y 1 = m(x – x 1 )

What is the point? What is the slope? Example 4: Graph the Line y – y 1 = m(x – x 1 )

What is the point? What is the slope? Example 5: Graph the Line

Choose the correct formula for each scenario. 1)Write a an equation for a line with a slope of 5 and a y-intercept of -2. 2)Write an equation for a line that includes the point (-7, 3) with a slope of ⅘. 3)Write an equation for a line with a slope of -⅞ and includes the point (8, 6). 4)Write an equation for a line with a y- intercept of 7 and a slope of -3. Slope Intercept y = mx + b m is the slope b is the y intercept Slope Intercept y = mx + b m is the slope b is the y intercept Point Slope y – y 1 = m(x – x 1 ) m is the slope (x 1, y 1 ) is a point on the line Point Slope y – y 1 = m(x – x 1 ) m is the slope (x 1, y 1 ) is a point on the line