解方程:(2x+1)2=-6x-3.
(2x+1)2=-6x-3
整理得(2x+1)2+3(2x+1)=0
即:(2x+1)(x+2)=0
x1=-0.5,x2=-2.
. Zhong Nanshan is a famous expert who has _____ to ____ the origin of SARS.
A.devoted; studying
B.been devoted; studying
C.devoted; study
D.been devoted; study
下列情况离子交换器需要大反洗()。
A、新装或新补加树脂后;
B、已运行10个周期;
C、周期制水量明显下降;
D、运行阻力明显增加。