We have to get to the root of the problem.

我们必须找到问题的根源。

《牛津词典》

We need to get to the root of the problem before we can solve it.

我们需要先弄清问题的根源，然后才能去解决它。

youdao

But with essential oils you can get to the root of the problem and banish this scourge once and for all.

但是精油可以得到该问题的根源，消除这一祸害一劳永逸。

youdao

And by making them go away you don't get to the root of your problem.

虽然恐慌症的症状得以消除,但你却无法找到问题的根源。

耶鲁公开课 - 心理学导论课程节选

"I think slapping a fine on a parent doesn't necessarily get to the root of the problem and doesn't necessarily do anything about it, " she said.

BBC: Kent parents fined most for child school absence

And Dan Stein of the Federation for American Immigration Reform says it doesn't get to the root of the problem, that employers use illegal immigrants to undercut US workers.

NPR: Kennedy, McCain Introduce Immigration, Guest Worker Bill

Representative TANCREDO: It does but it certainly also is hoping to get to the real root of the problem and the root of the problem is, of course, the magnet that is created by the employers who are, who are offering the jobs that people are taking and people who are here illegally are taking.

NPR: Colorado Congressman Fights Illegal Immigration