7: This looks quite bad. It is not a trig integral, because of the extra x. Thanks to it, no trig substitution would help. There is only one hope, try to get rid of that x using integration by parts. But what about the part you end up integrating? Perhaps it would be better if you try that bit first. So try to integrate the expression you get after taking away the x, this will tell you whether there is any hope for integration by parts.