Grade 8 Linear Functions Basics
Understanding Functions Linear Equations y = mx + b Solving One-Step Equations Graphing Linear Functions
What is a Function?
A function assigns exactly ONE output to each input Like a vending machine - put in money, get one specific snack Input → Function Rule → Output Each input has only one possible output
Function or Not a Function?
Look at these input-output examples Decide: Function or Not a Function? Remember: Each input can have only ONE output Use thumbs up for Function, thumbs down for Not a Function
Linear Equation: y = mx + b
y = output (what comes out) m = slope (how steep the line is) x = input (what goes in) b = y-intercept (where the line starts on the y-axis)
Understanding Slope and Y-Intercept
{"left":"Slope (m) tells us how steep the line is\nPositive slope = line goes up\nNegative slope = line goes down","right":"Y-intercept (b) is where the line crosses the y-axis\nIt's the starting point when x = 0\nExample: In y = 2x + 3, slope is 2 and y-intercept is 3"}
Solving One-Step Equations
Keep both sides balanced like a scale What you do to one side, do to the other Example: x + 3 = 7 Subtract 3 from both sides: x = 4
Practice: Solve These Equations
x + 5 = 12 y - 3 = 8 z + 7 = 15 Remember: Keep it balanced!
