What type of punctuation is necessary to set apart nonessential appositive phrases?

in 1636, roger williams settled at the tip of narragansett bay after being banished from the massachusetts bay colony for his religious views, on land granted to him by the narragansett tribe. he called the site "providence plantation" and declared it a place of religious freedom.

explanation:

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4