Question

2) If the points P[-1,-4 ) , Q ( b, c ) and R [5,-1] are collinear and if 2b + c = 4, then find the values of b and c
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Answer 1

Answer:

B=3

C= -2

Step-by-step explanation:

P (-1,-4),Q (b,c) and R (5,-1) are collinear.

That means slope of PQ=slope of PR=slope of QP

slope of PR= {-1-(-4)}/{5-(-1)}

= {-1+4}/{5+1}

=3/6=1/2

1/2=slope of PQ

1/2={c-(-4}/{b-(-1)}

=>1/2=(c+4)/(b+1)

=>b+1=2c+8

=>b+1=2 (4-2b)+8 [2b+c=4

c=4-2b]

=>b+1=8-4b+8

=>b+4b=16-1

=>5b=15

=>b=3

c=4-2b

=>c=4-2×3

=>c=4-6

c= -2

=>b=3

c= -2