3(5a^2+2a-1)-4(3-8a+2a^2)
问题描述：
3(5a^2+2a-1)-4(3-8a+2a^2)
答
7a^2+38a-15
答
3(5a^2+2a-1)-4(3-8a+2a^2)
=15a²+6a-3-12+32a-8a²
=7a²+38a-15
答
3(5a^2+2a-1)-4(3-8a+2a^2)
=15a^2+6a-3-12+32a-8a^2
=15a^2-8a^2+6a+32a-3-12
=7a^2+38a-15