已知4x²y-3y²=7,3x²y+4y²=19,求11x²y-2y²的值
问题描述:
已知4x²y-3y²=7,3x²y+4y²=19,求11x²y-2y²的值
答
4x²y-3y²=7.(1)
3x²y+4y²=19.(2)
(1)*2+(2):
11x^2y-2y^2=14+19=33