Find the values of a and b for which each of the following systems of linear equations has an infinite number of solutions:
(a – 1)x + 3y = 2,
6x + (1 – 2b)y = 6.
Given: (a – 1)x + 3y = 2 – eq 1
6x + (1 – 2b)y = 6 – eq 2
Here,
a1 = (a - 1), b1 = 3, c1 = - 2
a2 = 6 , b2 = (1 - 2b), c2 = - 6
Given that system of equations has infinitely many solution
∴ =
=
=
=
Here,
=
3×( - 6) = (1 - 2b)×( - 2)
- 18 = - 2 + 4b
4b = - 18 + 2
4b = - 16
b =
b = - 4
Also,
=
- 6(a - 1) = - 2×6
- 6a + 6 = - 12
- 6a = - 12 - 6
- 6a = - 18
a =
a = 3
∴ a = 3
∴ a = 3, b = - 4