Question

Find the equation of the line passing through the points A (2,1) B (7,9)

1) point slope

2) slope y-intercept

3) standard for

Answer 1

`m = (y_(2) - y_(1))/(x_(2) - x_(1)) = (9 - 1)/(7 - 2) = (8)/(5) = 1(3)/(5)`
y - y₁ = m(x - x₁)
y - 1 = 1³/₅(x - 2) Point - Slope Form
y - 1 = 1³/₅(x) - 1³/₅(2)
y - 1 = 1³/₅x - 3¹/₅
+ 1 + 1
y = 1³/₅x - 2¹/₅ Slope - Intercept Form
-1³/₅x - y = 1³/₅x - 1³/₅x - 2¹/₅
-1³/₅x - y = -2¹/₅
-1(-1³/₅x - y) = -1(-2¹/₅)
-1(-1³/₅x) + 1(y) = 2¹/₅
1³/₅x - y = 2¹/₅ Standard Form
1³/₅(0) - y = 2¹/₅
0 - y = 2¹/₅
-y = 2¹/₅
-1 -1
y = -2¹/₅ Y - Intercept
(x, y) = (0, -2¹/₅)