Which one is more efficiently and why? Replacing a iPhone battery that has been used for almost about 3 years or buying a new charger for it? Will give brainliest for this.

Consider an economy where the government's budget is initially balanced. the production function, consumption function and investment function can be represented as follows y equals k to the power of alpha l to the power of 1 minus alpha end exponent c equals c subscript 0 plus b left parenthesis y minus t right parenthesis i equals i subscript 0 minus d r suppose that taxes increase. what happens to the equilibrium level of output?