Solve using the elimination method. 5r-2s=21 & 2r+5s=20

How many temperature in biratnagar

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?