问题
解答题
计算: (1)(-3a3)2-a3+(-4a)2-a7+(-5a3)3; (2)30-23+(-3)2-(
(3)5x(x2+2x+1)-(2x+3)(x-5); (4)(2x-3y)(-2x-3y)+(x-4y)2. |
答案
(1)原式=9a9+16a9-125a9=-100a9;
(2)原式=1-8+9-2=0;
(3)原式=5x3+10x2+5x-(2x2-7x-15)=5x3+8x2+12x+15;
(4)原式=9y2-4x2+x2-8xy+16y2=25y2-8xy-3x2.