Ramona was asked to estimate the solution to the exponential equation 4x−300=42

by using an over/under table and providing her answer to two decimal places. She gave an estimated solution of x≈2.73
. In 3–5 sentences, explain why this is an unreasonable estimate of the solution to this equation.(4 points)

1 answer

The equation \(4^x - 300 = 42\) can be rearranged to \(4^x = 342\). To estimate \(x\), we can express \(4^x\) as \(2^{2x}\), which implies we are looking for \(2^{2x} = 342\). Since \(2^{10} = 1024\) and \(2^8 = 256\), we can infer that \(x\) should be slightly less than 8, since \(x\) must produce a value between these two powers of 2. Ramona's estimate of \(x \approx 2.73\) is unreasonable because it suggests \(4^{2.73} \approx 42\) which is much lower than 342. This sizable discrepancy indicates her estimate is not close to the actual solution.