Discover Questions

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? When the pressure that a gas exerts on a sealed container changes from -atm to 1.80 atm, the temperature changes from 86.0 C to 30.0 C.? =B y I y is an integer and ≤−4 Number Theory: Find the roots of 4x^2+6x+1 in Z11 (could you please explain step by step? THANKS!)? Describe how and where new crust material is made. Describe how and where old crust is destroyed.?