Question

how 63 is there in (10x+y)-(10y+x)

Answer 1

Answer:

As the reaction proceeds, bubbles of H2 (g) and a white precipitate of Ca(OH)2are formed. The bubbles formed stick to the surface of calcium metal and make it lighter. Therefore, Calcium floats on water. ... Hence, hydrogen does not catch fire.

Answer 2

$(10x + y) - (10y + x) \\ 10x + y - 10y - x \\ 10x - x + y - 10y \\ 9x - 9y \\ 9(x - y)$