Rosa says 4x and -6x are like terms, so they can be combined. Tiffany says 5a and 5b are like terms, so they can be combined. Is Rosa correct? Is Tiffany correct? Why or why not? please help =)

Aswimming pool is a rectangle with semicircles on the end. the rectangle is 12 meters wide and 30 meters long. the diameter and width of the swimming pool are equal. sketch and label an overhead diagram of the swimming pool. find the area of the swimming pool floor.

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?

I’m really confused and need your assist me with this question i’ve never been taught