化简:(1)-5(x^2-3)-2(3x^2+5) (2)2m-3n+[6m-(3m-n)]
问题描述:
化简:(1)-5(x^2-3)-2(3x^2+5) (2)2m-3n+[6m-(3m-n)]
答
(1)-5(x^2-3)-2(3x^2+5)
= -5x^2+ 15 -6x^2 -10
= -11 x^2 + 5
(2)2m-3n+[6m-(3m-n)]
= 2m -3n + 6m - 3m +n
= 5m -2n