What is the solution of the following system? -2x-y=1 -4x-2y=-1 a) infinitely many solutions b) no solutions c) (3,8) d) (-3,-8)

Evaluate the following expression 1/3^2

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals