Answer: He spend $36 in all and $9 for tax and tip.
Explanation:
Since we have given that
Amount of bill for dinner = $45
Rate of tax = 5%
Rate of tip = 15%
Amount of tax would be

Amount of tip would be

total amount he spend for tax and tip combined is given by

Amount he spend in all is given by

Hence, he spend $36 in all and $9 for tax and tip.