Solve and express the solution set in simplest form. 8x-2/9 = 2/1

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

Aefg - almn. find the ratio of aefg to almn. a)1: 4 b)1: 2 c)2.1 d)4: 1

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"