Can you combine like terms without formally showing the distributive property? explain.

Yes you can! Say you have 5(2 + x) + 3x. The answer would be 10+8x because when you use the distributive property you will end up getting 5*2 5*x and once you multiply, it's obvious 5 times 2 is 10 and 5 times x will equal 5x. Then you add 5x and 3x and get 8x. So, the simplified expression here is 10+8x. When you have this as an answer it's proving your answer right. You can without using the distributive property. We can have 10+5x+3x and it will be your simplified expression. It's the same thing with equations too.