Mathematics - Calculus - Multivariable - Multiple integrals - Evaluate Double Integrals

8 problems: (1-2) Rectangular regions: ∫₀¹∫₀²(2x+3y)dydx, ∫₁³∫₀²x²y dydx. (3-4) Non-rectangular: ∫₀¹∫₀ˣ xy dydx, ∫₀²∫₀^(x²) 1 dydx. (5) Change order of integration: given ∫₀¹∫ᵧ¹ f(x,y)dxdy, rewrite with dx inside. (6) Volume: volume under z=4-x²-y² above xy-plane. (7) Average value of f(x,y)=xy over