(20-x)(32-x)=320

问题描述:

(20-x)(32-x)=320

(20-x)(32-x)=320
640-20x-32x+x²=320
x²-52x=-320
x²-52x+676=356
(x-26)²=356
x-26=√356
x=±2√89+26
∴x1=2√89+26
x2=-2√89+26