Question

if pt A(-2,1),B(a,b)&C(4,-1) as collinear and a-b=1,find the value of a&b

Answer 1

a=1 and b=0 since the line is collinear and also touches 1 in the x axis

Answer 2

since the slope of AB = BC = AC
slope of AB =(b-1)/(a+2)
BC= (-1-b)/(4-a)
AC= -2/6 = -1/3
SO
(b-1)/(a+2)=-1/3
3b-3=-a-2
a+3b=1
a-b=1 given
a-b+4b=1
1+4b=1
b=0
a=1