The microsphere nanoscope is a powerful tool that allows humans to see structures 9 × 10–9 meter in diameter. How is this number expressed in standard form?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2

Aliter of water contains about 3.35 x 10^25 molecules. a certain river discharges about 2.9x 10^8 l of water every second. about how many molecules does the river discharge every minute? write your answer in scientific notation