问题
填空题
与代数式8a2-6ab-4b2的和是4a2-5ab+2b2的代数式是______.
答案
根据题意得(4a2-5ab+2b2)-(8a2-6ab-4b2)
=4a2-5ab+2b2-8a2+6ab+4b2=(4-8)a2+(6-5)ab+(2+4)b2
=-4a2+ab+6b2
故填-4a2+ab+6b2.
与代数式8a2-6ab-4b2的和是4a2-5ab+2b2的代数式是______.
根据题意得(4a2-5ab+2b2)-(8a2-6ab-4b2)
=4a2-5ab+2b2-8a2+6ab+4b2=(4-8)a2+(6-5)ab+(2+4)b2
=-4a2+ab+6b2
故填-4a2+ab+6b2.