How do I unlock the two green mushrooms on world 7?

I can't figure out the second one either, but for the first one you need to find the red flag in the ghost house. Here's what you do:

When you enter, hit the first brick to reveal the ?, and jump on the ? To unlock the six gold doors. Enter the botton right door. Jump to hit the hidden box that reveals another ?. Jump on that to reveal the two floating platforms and take them up to the door. Once in the door, you will see a ton of gold coins. Jump on the blue P to make the coins turn to bricks. If you go Right, you will find the last Gold Star Coin and finish the level. You need to go Left. Run super fast and about halfway to the far left wall, you need to jump and hit the upper level of bricks to reveal a vine (it's the third brick from the right in the long row of bricks). Go back a few steps to jump up to that level and climb the vine to the door which will take you to the red flag. You have to be really quick or the bricks will turn back to gold coins and you will fall/die. Good luck!

The second life house (green mushroom) can be reached by finding a second red flag through world 7-4. You will need mini Mario to do it. Use the bouncy pink platforms and spinning platforms to reach to highest platform you can. That's where you need to be to get the third coin. On that top pink bouncy platform, you will see a winged ? Box floating up and down. Jump on top of that. From there, jump into the indented space on the left. You can see a tiny pipe to your left. You need to run out of the indented platform and jump up to get over the wall. That allows you to get to the tiny pipe which will take you to the red flag.