Discover Questions

How many molecules are in 97.8g of FeCl3? Is there a musical term for two independent, non-complementary, parts being played simultaneously? What about for three parts? What is 4 x 6? Could someone help me with these math problems? I can't figure them out. Solve the linear equation;
x+2y=15
y=-2x+0 9x-12y=-3
-12x+16y=4? Describe how and where new crust material is made. Describe how and where old crust is destroyed.?