x=?
log215−log214≤log21x−log213
To solve the inequality involving logarithms with base 21, we will perform the following steps:
- Step 1: Apply the subtraction property of logarithms.
- Step 2: Simplify and solve the inequality.
Let's go through the steps:
Step 1: Simplify both sides using the logarithm subtraction rule:
Left side: log215−log214=log21(45)
Right side: log21x−log213=log21(3x)
This gives us the inequality:
log21(45)≤log21(3x)
Step 2: Since 21 is less than 1, the inequality sign flips when we remove the logarithms.
This gives: 45≥3x
Multiplying both sides by 3 to solve for x:
3⋅45≥x
415≥x
Thus, x≤415, which simplifies to x≤3.75.
Since we assumed x>0, the final solution is:
0<x≤3.75