For the following equations, what are the values of a and b to have infinitely many solutions?
ax + by = 2
3x - (5 - 2a)y = 6
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. a = 1,b = - 1.
Condition for infinitely many solutions is: If there are two equations, say;
a1x + b1y = c1 and a2x + b2y = c2
Then,
According to the given question, the two equations are:
ax + by = 2
3x - (5 - 2a)y = 6
⇒
⇒ 6a = 6
⇒ a = 1
Now,
⇒ 6b = -2(5 - 2)
⇒ 6b = -6
⇒ b = -1
Hence the values of a and b to have infinitely many solutions are a = 1,b = - 1.