y = mx + b "m" is the slope, "b" is the y-intercept (the y value when x = 0)
1. slope: -3
y-intercept: 7
y = -3x + 7
Your answer is B
y + 3x = 7 Subtract 3x on both sides
y = -3x + 7
2. y + 9(x + 3) = 0 Multiply/distribute 9 into (x + 3)
y + 9x + 27 = 0 Subtract 9x and 27 on both sides to get "y" by itself
y = -9x - 27
slope: -9
y-intercept: -27 or (0,-27)
Your answer is D
3. Point-slope form: y - y₁ = m(x - x₁)
slope: -11
(x₁ , y₁) = (-5, 7)
y - 7 = -11(x - (-5)) The two negative signs becomes a positive
y - 7 = -11(x + 5)
Your answer is C
4. For this question, I think you get it from point-slope form to slope-intercept form (I'm not sure, but you still get the same answer if you just do slope-intercept form)
slope: -4
(x₁ , y₁) = (2, -8)
y - y₁ = m(x - x₁)
y - (-8) = -4(x - 2)
y + 8 = -4(x - 2) Multiply/distribute -4 into (x - 2)
y + 8 = -4x + 8 Subtract 8 on both sides to get "y" by itself
y = -4x
Your answer is A
