(80-2x)(50-2x)=5400rt
问题描述:
(80-2x)(50-2x)=5400
rt
答
[2(x-40)][2(x-25)]=5400
(x-40)(x-25)=5400÷4
x²-65x+1000=1350
x²-65x-350=0
(x-70)(x+5)=0
x=70,x=-5