解方程:(44-x)(20+5x)=1600.
问题描述:
解方程:(44-x)(20+5x)=1600.
答
方程可化为880+220x-20x-5x2=1600,
5x2-200x+720=0,
x2-40x+144=0,
(x-4)(x-36)=0,
x1=4,x2=36.