How many significant figures does 076.0128 have?

Find the value of the variable and the length of each secant segment

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?

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10