Microeconomics: Assume that consumer's utility function...

Assume that a consumer's utility function is U (c1, c2) = (cj + c2) ? with pequal to -0.5 , where c1 denotes consumption in 2021, and c2 denotes consumption in 2022. The consumer's income in 2021 will be 20.000 dollars, in 2022 it will be 0 dollars: thus the consumer has to save part of his 2021 income to consume in 2022. The interest rate between the two periods is 10%. How much does the consumer consume in 2021? How much does she consume in 2022? * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *? Assume that the interest rate changes from 10% to 20%. How much does the consumer consume in 2021 in this case? How much does she consume in 2022 in this case? What is the substitution effect of this change in interest rate on 2021 consumption (using Hicksian decomposition)