y=[100-(x-20)*10]*(x-18)计算过程
问题描述:
y=[100-(x-20)*10]*(x-18)计算过程
答
解 y=[100-(x-20)*10]*(x-18)
=[100-10(x-20)](x-18)
=[100-10x+200](x-18)
=(300-10x)(x-18)
=300x-5400-10x^2+180x
=-10x^2+480x-5400