Two-Step Equations
9x - 7 = -7
x = 0
On a graph, we find slope by counting _____ over ____.
Rise, run
Write an equation of a line that has a slope of -2 and a y-intercept of 7 in slope-intercept form.
y = -2x + 7
Suppose you solve the system of equations below using elimination.
-4x + 7y = 18
4x + 2y = -9
The x terms will cancel out. Why?
When graphing inequalities, when do we shade above the line? When do we shade below?
Above when sign is greater than, below when sign is less than
2(n + 5) = -2
n = -6
If a line is going up from left to right, what type of slope is it? If a line is going down from left to right, what type of slope is it?
Positive, negative
Write an equation in point-slope form of a line that has a slope of 1/3 and the point (6, 7).
y - 7 = 1/3(x - 6)
Solve by substitution
y = 2x
3x + 2y = 14
(2, 4)
When do we draw solid lines on a graph? When do we draw dashed lines?
-9x + 1 = -80
x = 9
Find the slope of the line that connects the points (4, 10) and (1, 8)
2/3
Write an equation in point-slope form that has a slope of -3 and the point (-4, -9).
y + 9 = -3(x + 4)
Solve by elimination
5x + 3y = 17
x - 3y = 7
(4, -1)
Solve 2x - 7 < 15
x < 11
144 = -12(x + 5)
x = -17
Find the slope of the line that connects the points (5, 7) and (6, 2)
-5
Rewrite 3x + 2y = 16 in slope-intercept form.
y = -3/2x + 8
Solve by elimination
-3x + 2y = 8
-6x + 7y = -8
(-8, -8)
Solve -2x - 7 < 15
x > -11 (flip the inequality sign)
8 + (b/-4) = 5
b = 12
Find the slope of the line that connects the points (3, -8) and (6, -1)
-7/3
Write a slope-intercept form equation of a line that has a slope of -4 and runs through the point (-2, 13)
y = -4x + 5
Solve by substitution
x = 2y + 4
-4x + 6y = -10
(-2, -3)
Rewrite the inequality 5x - 6y > 36 in slope-intercept form.
y < 5/6x - 6