Question

The real roots of the equation $7^{\log 7(x^{2} - 4x + 5)}$= x–1 are-

• A. 1 and 2
• B. 2 and 3
• C. 3 and 4
• D. 4 and 5

Answer 1

Answer: (B)

2 and 3

Answer 2

Since $a^{\log_{a}x}$= x " a > 0 and a ¹ 1

Here x² –4x + 5 > 0

Ž x > 0 x Ī R because D = 16 – 20 < 0

We have x² – 4x + 5 = x –1

Ž x² –5x + 6 = 0 Ž x = 2 and 3

Hence correct choice i