Question

Write an equation for the line whose slope is 7/2 and which contains the point (-12,-9)

Answer 1

Slope-intercept form:

y = mx + b    "m" is the slope, "b" is the y-intercept (the y value when x = 0)

Since you know m = 7/2, plug it into the equation

y = 7/2x + b  

To find "b", plug in (-12,-9) into the equation

y = 7/2x + b

-9 = 7/2(-12) + b

-9 = -84/2 + b

-9 = -42 + b     Add 42 on both sides

33 = b

$y=\frac{7}{2}x+33$

(if you're not suppose to use slope-intercept form)

Point-slope form:

y - y₁ = m(x - x₁)

m = 7/2

(x₁ , y₁) = (-12,-9)

Plug this into the equation

y - y₁ = m(x - x₁)

y - (-9) = 7/2(x - (-12))

$y+9=\frac{7}{2}(x+12)$