4a^2-9b^2+16a^2+24ab+9b^2-5ab+5a^2
4×16-9×100+16×16+24×(-4)×10+9×100-5×(-4)×10+5×16=64-900+256-960+900+200+80= -360
4a^2-9b^2+16a^2+24ab+9b^2-5ab+5a^2
4×16-9×100+16×16+24×(-4)×10+9×100-5×(-4)×10+5×16=64-900+256-960+900+200+80= -360