If 3x+20=2y and x+5=y show that (2,7) is a solution solve by substitution. answer me

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

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

When x = 3 and y = 5, by how much does the value of 3x2 – 2y exceed the value of 2x2 – 3y ?