Answer:
Step-by-step explanation:
2{5x²-15+(-9xy²)}-(2y²+4x-xy²)+3x²
=2{5x²-15-9xy²}-(2y²+4x-xy²)+3x²
=10x²-30-18xy²-2y²-4x+xy²+3x²
=13x²-2y²-17xy²-4x-30
