diketahui persamaan garis y= mx+c. tentukan nilai m dan c jika garis tersebut melalui titik: a. (2,1) dan (-3, -1) b. (2,0) dan (0,4) c. (-4, 2) dan (3,-3) tolo

Rumus : (y - y₁) = (x - x₁)(y₂ - y₁) / (x₂ - x₁)

a. (y - 1) = (x - 2)(-1 - 1) / (-3 - 2)
y - 1 = (x - 2)(-2) / (-5)
-5y + 5 = -2x + 4
5y = 2x + 1
y = [tex] \frac25x + \frac15 [/tex]

m = 2/5 , c = 1/5

b. (y - 0) = (x - 2)(4 - 0) / (0 - 2)
y = (x - 2)(4) / (-2)
-2y = 4x - 8
y = -2x + 4

m = -2 , c = 4

c. (y - 2) = (x - [-4])(-3 - 2) / (3 - [-4])
y - 2 = (x + 4)(-5) / (7)
7y - 14 = -5x - 20
7y = -5x - 6
y = - ⁵/₇ x - ⁶/₇

m = -5/7 , c = -6/7