When caleb verified his solution it didn’t work what mistake did he make

Im gonna fail 7th grade selective breeding 1. creates offspring which are genetically identical to the parent 2. is the process of breeding only organisms with desirable traits 3. involves the removal of the nucleus of a cell 4. combines traits from organisms of different species

!! 10 ! a westbound jet leaves central airport traveling 635 miles per hour. at the same time, an eastbound plane departs at 325 miles per hour. in how many hours will the planes be 1900 miles apart?

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.