Mathematical problems of triangular circles

First of all, I want to confirm that the title of this question is:

Find the value of triangle and circle

According to the meaning of the question, the following equations can be listed.

{2△+○=42①

{△+○=25②

Here we can get an equation from ①-②.

△= 17

So the value of △ is 17.

Next, you can substitute △= 17 into ② (or ①, of course) to get another equation.

17+○=25

Minus 17 on both sides, so.

○=8

So the value of △ is 17, and the value of △ is 8.

If you don't understand, you can ask.