I found _____ impossible for_____ to work out the maths prob

I found it impossible to work out this maths problem 不加be动词也 I tried to get out of the business _____ I found impossible I have some problems/difficulty/trouble to work out the prob All of us found ( )difficult to work out the maths problem. All of us found hard to work out the maths problem 为什么答案是it 23.I tried to get out of the business I found impossible. i tried to get out of the business,___ i found impossible I found that diffcult to work out the problem 改错 I found()impossble for()to work out the math problem I found ___ not easy to work out the problem, 1.I found it was impossible to finish the work in two hours It's impossible for him to work out this Maths probiem.