Question

If the lines ax-y-b=0 and x-2by+a =0 meet at points (1, 2) then find a and b

Answer 1

Hi Mate!!

The given two lines meets at a point ( 1,2) means this point lies on both the lines.

i,e x = 1 and y = 2

a ( 1 ) -2 - b = 0

=>. a - b = 2 .... equation 1

And

( 1 ) - 2 ( b ) ( 2 ) + a = 0

=>. a - 4b = -1 equation 2

Subtract equation 2 from 1

=>. 3b = 3

=>. b = 1

Now put value of b in equation 1

we get a = 3

Have a nyc tym

Answer 2

first ax-y=0
given (1,2) here x=1 and y=2
now put the value of x and y in above equation
a(1)-2=0
a=-2 ........(1)

again same
put the value of second equation
1-2b2+a=0
a-4b=1........(2)

now by elimination metho
a-4b=1
a. =-2. change the sign of below numbers
______
-4b=3
b=-3/4

now put the value of b in any equation
so a=2 and b = -3/4