How do you write an equation in standard form for a line passing through P(6, 2), Q(8, -4)?
1 Answer
May 12, 2015
Standard line equation: y = ax + b. Find a and b.
Line passing at point ( 6, 2)
2 = 6a + b -> b = 2 - 6a
Line passing at point (8, -4)
-4 = 8a + b = 8a + (2 - 6a) = 2a + 2. -> 2a = -6 -> a = -3 -->
b = 2 - 6a = 2 + 18 = 20.
Answer: y = -3x + 20.
Check with point (6, 2):
y = 2 = -3(6) + 20 = -18 + 20 = 2 Correct
Check with point (8, -4):
y = -4 = -24 + 20 = -4 . Correct.
