(2014•岳阳)下列因式分解正确的是( )
A.x2﹣y2=(x﹣y)2 B.a2+a+1=(a+1)2 C.xy﹣x=x(y﹣1) D.2x+y=2(x+y)
(2014•毕节市)下列因式分解正确的是( )
A.2x2﹣2=2(x+1)(x﹣1)
B.x2+2x﹣1=(x﹣1)2
C.x2+1=(x+1)2
D.x2﹣x+2=x(x﹣1)+2
(2014•葫芦岛)计算:552﹣152=( )
A.40 B.1600 C.2400 D.2800
(2014•河北)计算:852﹣152=( )
A.70 B.700 C.4900 D.7000
(2014•仙桃)将(a﹣1)2﹣1分解因式,结果正确的是( )
A.a(a﹣1) B.a(a﹣2) C.(a﹣2)(a﹣1) D.(a﹣2)(a+1)
(2014•衡阳)下列因式分解中,正确的个数为( )
①x3+2xy+x=x(x2+2y);②x2+4x+4=(x+2)2;③﹣x2+y2=(x+y)(x﹣y)
A.3个 B.2个 C.1个 D.0个
