Discover Questions

Describe how and where new crust material is made. Describe how and where old crust is destroyed.? If x^2+y^2 = 6, and x+y=3, then what is x^3+y^3? 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? Problem involving math induction! 1. Prove for every integer p, p^2 + 3p + 8 is even.? Make a conjecture about the next item in the sequence.1, -4, 9, -16,?