(x/4)^2+[(20-x)/4]^2=17怎么得到的下一步(x/4)²+[(20-x)/4]²+2(x/4_数学解答

(x/4)^2+[(20-x)/4]^2=17怎么得到的下一步(x/4)²+[(20-x)/4]²+2(x/4) [(20-x)/4]=17+2(x/4) [(20-x)/4]

人气：384 ℃　时间：2020-06-30 02:36:10

解答

(x/4)²+[(20-x)/4]²=17
(x/4)²+[(20-x)/4]²+2(x/4) [(20-x)/4]=17+2(x/4) [(20-x)/4]
[x/4+(20-x)/4] ²=17+x(20-x)/8
25=17+x(20-x)/8
x(20-x)=64
x²-20x+64=0
(x-16)(x-4)=0
x1=16,x2=4