1.4a²-2（ab-3a²）+3 2.3x²-【7x-（4x+2）+2x²】-x²谢谢.拜托

1.4a²-2（ab-3a²）+3 2.3x²-【7x-（4x+2）+2x²】-x²谢谢.拜托
1.4a²-2（ab-3a²）+3 2.3x²-【7x-（4x+2）+2x²】-x²
谢谢.拜托

1.4a²-2（ab-3a²）+3 2.3x²-【7x-（4x+2）+2x²】-x²谢谢.拜托
1.4a²-2（ab-3a²）+3
=4a²-2ab+6a²+3
=10a²-2ab+3
2.3x²-【7x-（4x+2）+2x²】-x²
=3x²-7x+4x+2-2x²-x²
=-3x+2

1. 原式=4a^2-2ab+6a^2+3=10a^2-2ab+3

2. 原式=3x^2-[7x-4x-2+2x^2]=3x^2-[2x^2+3x-2]=3x^2-2x^2-3x+2=x^2-3x+2