(2, a) and (5, - 3) is parallel to(4, 8) and (- 5, a + 1) , what's value of a

Question

If the line passing through the points (2, a) and (5, - 3) is parallel to the line passing through the points (4, 8) and (- 5, a + 1) , what is the value of a

Answer 1

line 1...points (2,a) & (5, -3)

deltax=5-2=3

deltay=-3-a

slope1=deltay/deltay=3/(-3-a)...-3/(a+3)

line 2...(-5, a+1) (4,8)

deltax=9, deltay=8-a-1  =7-a

slope2=(7-a)/9

tu be parallel, slope1=slope2...[-3/(a+3)] = [(7-a)/9]=-(a-7)/9

[27/(a+3)]=(a-7)

(a+3)*(a-7)=27

x^2 -4x -21-27=0   or x^2 -4x -48=0

a=9.2111026 or =-5.2111026

from quadratik equashun..-b/2a=2, b^2-4ac=208,  root=14.422205102,

root/2a=k7.211102550