数学初一计算题(时间快又对的加分)
问题描述:
数学初一计算题(时间快又对的加分)
(1)3x²y — [2x²y —(2xyz—x²z)—4x²z]
(2)3a²b—[a²c—(3abc+2a²c)+5a²b]—3abc
注:
答
3x²y — [2x²y —(2xyz—x²z)—4x²z]=3x²y -2x²y+(2xyz—x²z)+4x²z=3x²y -2x²y+2xyz—x²z+4x²z=x²y+2xyz+3x²z
3a²b—[a²c—(3abc+2a²c)+5a²b]—3abc=3a²b—a²c+(3abc+2a²c)-5a²b—3abc=3a²b—a²c+3abc+2a²c-5a²b—3abc=a²c-2a²b