Sorry..... 23-12=11 right? And why 23-12? May I ask you to explain?

We need to find how many years time. If you don't understand than you can do another senorio which is 23×2-35=11.Sorry l did a careless mistake.

Ok.... I try to understand. Thanks Mhiru

If you have any more problems just inform me
I will try to solve it

Thank you, Mhiru

To improve your maths skills you can watch some math questions and how they solve it. You can even pause the video and try the question yourself and after that you can continue the video to see if your answer is correct. If you do not know how to solve it you can learn yourself. By doing this l believe you can do your best you can just squeeze your brain. And let numbers flow like birds