Report

How do you find b? How do you find b? How do you find b? “DRY” How do you find b (dry)? Review What is slope-intercept form? Y = mX + b ? Review What is slope-intercept form? Y = mX + b Input Review What is slope-intercept form? Y = mX + b ? Review What is slope-intercept form? Y = mX + b Output Review What is slope-intercept form? Y = mX + b ? Review What is slope-intercept form? Y = mX + b Rate of change a.k.a. Slope Review What is slope-intercept form? Y = mX + b ? Review How do you find b? What is slope-intercept form? Y = mX + b Starting amount a.k.a. ‘y-intercept’ Riddle b I started with some money. m Every week I earned $100. After 4 weeks, I had $900. How much did I start with? X Y Riddle b I started with some money. m Every week I earned $100. X Y 4 900 After 4 weeks, I had $900. How much did I start with? Riddle b I started with some money. m Every week I earned $100. X After 4 weeks, I had $900. 1 Y 0 2 How much did I start with? 3 4 900 Riddle b I started with some money. m Every week I earned $100. X After 4 weeks, I had $900. 1 Y 0 2 How much did I start with? 3 800 4 900 Riddle b I started with some money. m Every week I earned $100. X After 4 weeks, I had $900. 1 How much did I start with? Y 0 2 700 3 800 4 900 Riddle b I started with some money. m Every week I earned $100. X After 4 weeks, I had $900. 1 600 2 700 3 800 4 900 How much did I start with? Y 0 Riddle b I started with some money. $500 m Every week I earned $100. X Y 0 500 After 4 weeks, I had $900. 1 600 2 700 3 800 4 900 How much did I start with? 900 – 400 4 * 100 Gained $400 Started with $500 “DRY” Write the equation of the linear relationship with: m m: 100 x y point: (4, 900). Y = mX + b 900 = 100(4) + b 900 = 400 + b – 400 Y = 100X + 500 –400 500 = b Ex. 1: Write the equation of a line that goes through (7, 8) and has a slope of 2. Y = mX + b NEED m and Y = 2X – 6 b NEED b!!! How to use (7, 8)??? Input X Output Y Ex. 1: Write the equation of a line that goes through (7, 8) and has a slope of 2. Y = mX + b Y = 2X – 6 8 = 2(7) + b 8 = 14 + b – 14 – 14 -6 = b How to use (7, 8)??? Input X Output Y Ex. 2: Write the equation of a line with this information: m slope: -5 X Y point: (-4, 3) Y = mX + b 3 is NOT y-intercept!!! Ex. 2: Write the equation of a line with this information: m slope: -5 X Y point: (-4, 3) Y = mX + b 3 = -5(-4) + b 3 = 20 + b – 20 – 20 -17 = b Y = -5X – 17 Ex. 3: Write the equation of a line that goes through (0, 8) and has a slope of 2. Y = mX + b NEED m and b Y = 2X + 8 Ex. 3: Write the equation of a line that goes through (0, 8) and has a slope of 2. Y = mX + b NEED m and b Y = 2X + 8 Ex. 4: Write a rule from this information: m m: -4 X Y point: (8, -2) Y = mX + b -2 = -4(8) + b -2 = -32 + b + 32 + 32 30 = b Y = -4X + 30 Ex. 5: Write an equation for a relationship with this information: m: zero. point: (-4, -6) Y = -6 The change in y when x increases by one Ex. 6: Write an equation for a relationship with this information: m: undefined. point: (-4, -6) X = -4 The change in y when x increases by one The End