gr10 writing linear equations
TRANSCRIPT
Writing Linear Equations Using Slope Intercept Form
Slope-Intercept Form
• y = mx + b (c) [or f(x) = mx + b]
• m is the slope/gradient• b/c is the y-intercept
Find the Equation of the Line
• What is the
y-intercept?• b = -2• What is m?• m = • y = x -2
x
y
3
23
2
Find the Equation of the Line
• b = ?• b = 1• m = ?• m = -
• y = - x + 1
x
y
1
21
2
Find the Equation of the Line
• b = ?• b = 4• m = ?• m = 0 • y = 0x+4• y=4
x
y
Find the Slope and y-intercept of each Equation:1) y = -4x + 3
m = -4
b = 3
2) y = 5 - x
m = -
b = 5
3) 8x + y =
m = -8
b =
4) 4x - 2y = 10
m = 2
b = -5
1
21
2
3
4
3
4
Find the Equation Given the Slope and y-intercept
1) m = -3, b = 1
y = -3x + 1
2) m = - , b = -4
y = - x - 4
2
52
5
Find the Equation Given the Slope and a Point
Given m = -1, (2, 1)
First, calculate b by substituting the slope and the coordinates into y = mx + b.
y = -1x + b
1 = -1(2) + b
1 = -2 + b
3 = b
y = -1x + 3
Write the equation.
gradient = 2, passes through (-4, 6)
slope = -3/2, passes through (5, 3)
Find the Equation GivenTwo PointsGiven (-1, 3) and (2, 1)
First, calculate the slope:
Second, find b. Use either point...m = , (2, 1)
1 = (2) + b
1 = + b
= b
( )
( )m
1 3 2
2 1 3
2
3
2
3
4
3
7
3y x
2 7
3 3
Write the equation
passes through (6, 1) and (8, -4)
Passes through (-3, 5) and (2, 2)