Question

answer correct
answer correct
with explanation only​

Answer 1

Step-by-step explanation:

We have,

$\tt{ {x}^{2} - (2a + 1)x + ( {a}^{2} + a) < 0}$

$\tt{ \implies{x}^{2} - ax - (a + 1)x +a (a + 1) < 0}$

$\tt{ \implies \: x(x - a) - (a + 1)(x - a ) < 0}$

$\tt{ \implies \: (x - (a + 1))(x - a) < 0}$

$\tt{ \implies \: x \in(a , a + 1)}$

But $\sf{x\in(-1,2)}$

So,

$\tt{ \implies \: ( - 1,2) \in(a , a + 1)}$

$\tt{ \implies \: - 1 = a \: \: \: \: \: and \: \: \: \: a + 1 = 2}$

Which is not possible,

Answer 2

Answer:

See this attachment..

Step-by-step explanation:

Option :- 2 is the answer..

Hope its help..