1.if a line with a slope of -3 crosses the y-axis at (0,7), what is the equation of the line? a. y - 3x = 7 b. y + 3x = 7 c. y = -3(x + 7) d. y = -3x - 7 2. find the slope and the y-intercept of the equation y + 9(x+3) = 0 a. slope: -9 y-intercept: (0,-3) b. slope: 9 y-intercept: (0,-3) c. slope: 9 y-intercept: (0,27) d. slope: -9 y-intercept: (0,-27) 3. given a line with a slope of -11 and going through the point (-5,7), provide an equation in point-slope form. a. y + 7 = 11(x + 5) b. y - 7 = 11(x - 5) c. y - 7 = -11(x + 5) d. y + 7 = -11(x - 5) 4. what is the point-intercept form of the equation of a line that passes through point (2,-8) with a slope of -4? a. y = -4x b. y = 4x - 16 c. y = 4x d. y = -4x + 16

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

step-by-step explanation:

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: