If log10 5 + log10 (5x + 1) = log10 (x + 5) + 1 = log10 (x + 5) + 1, then x equals:
A. 1
B. 3
C. 5
D. 10
Answer:B
If log10 5 + log10 (5x + 1) = log10 (x + 5) + 1 = log10 (x + 5) + 1, then x equals:
A. 1 B. 3 C. 5 D. 10
Explanation: log10 5 + log10 (5x + 1) = log10 (x + 5) + 1 log10 (x + 5) + 1 log10 (x + 5) + 1 log10 (x + 5) + 1,log10 5 + log10 (5x + 1) = log10 (x + 5) + log10 10 = log10 (x + 5) + log10 10,5 (5x + 1) log10 [10(x + 5)] = log10 [10(x + 5)],10(x + 5) = 5(5x + 1),2x + 10 = 5x+1,3x =9,x equals 3.