Solve the equation 2^(3x−1) = 5(3^(1−x)). Give your answer in the form (ln a)/(ln b) where a and b are integers.
- Solve the equation 2^(3x−1) = 5(3^(1−x)). Give your answer in the form (ln a)/(ln b) where a and b are integers.[4]
Mark scheme
Marking points from the official mark scheme (Oct/Nov 2022). The mark or mark type is shown in brackets.
- [M1] Use law of the logarithm of a power or product
- [A1] Obtain a correct linear equation in any form, e.g. (3x-1)ln2 = ln5+(1-x)ln3
- [M1] Solve for x
- [A1] Obtain final answer x = ln 30 / ln 24
- [M1] (Alternative method) Use laws of indices to split at least one exponential term
- [A1] (Alternative method) Obtain 24^x = 30
- [M1] (Alternative method) Solve for x
- [A1] (Alternative method) Obtain final answer x = ln 30 / ln 24
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →