Calculating value of company

Dear John, When provided with the following details, which is the correct method of calculating post aquisition company value? : Details -Most recent profit after tax for aquirer and aquirer on their own, pre aquisition -P/E ratio after aquisition -Synergy p.a. created from aquisition I am uncertain if I should use bootstrapping or add synergy onto individual company values pre aquisition My uncertainty arises because the P/E ratio of joint company post aquisition is LESS than the P/E ratio of the acquiree company on its own. Does it have a bearing on which method I should use the fact that it is less? Kind regards