Question

Determine the value of k for which the following pair of linear equations represents a pair of coincident lines on

the graph :
3x + 4y = k + 1 ; 6x + 8y = 10.​

Answer 1

Answer:

3x+4y=k+1......(1)

6x+8y=10.......(2)

the above equation can be rewritten as

3x+4y-k+1=0......(3)

6x+8y-10=0.......(4)

comparing the above equation

a1x+b1y+c1=0 and a2x+b2y+c2=0

a1=3 ; b1=4 ; c1 = -(k+1)

a2=6 ; b2=8 ; c2= -10

a1/a2=b1/b2=c1/c2

3/6=4/8= -k+1/-10

1/2=1/2=k+1/10

1/2=k+1/10

k+1=5

k=4