计算（3y-1)(2y+3)-(6y-5)(y-4)
问题描述：
计算（3y-1)(2y+3)-(6y-5)(y-4)
答
（3y-1)(2y+3)-(6y-5)(y-4)
=（6y²+7y-3)-(6y²-29y+20)
=36y-23