21log3(x4)=log3(3x2+5x+1)
x=?
To solve the equation 21log3(x4)=log3(3x2+5x+1), we will first use the power property of logarithms.
Step 1: Apply the power property to the left side: 21log3(x4)=log3(x4)21=log3(x2).
Step 2: Now, equating the arguments on both sides, we have: x2=3x2+5x+1.
Step 3: Rearrange the equation to form a standard quadratic: 0=2x2+5x+1 or 2x2+5x+1=0.
Step 4: Solve the quadratic using the quadratic formula: x=2a−b±b2−4ac, where a=2, b=5, and c=1.
Step 5: Substitute the coefficients into the quadratic formula:
xamp;=2⋅2−5±52−4⋅2⋅1amp;=4−5±25−8amp;=4−5±17
Since we need the solutions to keep the arguments of the logarithms positive, we ensure that 3x^2 + 5x + 1 > 0 for values of x from our solution set.
Thus, the solutions satisfying these conditions are given by x=−45±417. Therefore, the correct answer is choice 1: −45±417.
−45±417