题目内容
(请给出正确答案)
[单选题]
下列等式能够成立的是()
A.(x-y)²=x²-xy+y²
B.(x+3y)²=x²+9y²
C.(x-y/2)²=x²-xy+y²/4
D.(m-9)(m+9)=m²-9
答案
C、(x-y/2)²=x²-xy+y²/4
如果结果不匹配,请 联系老师 获取答案
A.(x-y)²=x²-xy+y²
B.(x+3y)²=x²+9y²
C.(x-y/2)²=x²-xy+y²/4
D.(m-9)(m+9)=m²-9
C、(x-y/2)²=x²-xy+y²/4
A.(X-Y)-Z=X-(Y∩Z)
B.(X-Y)-Z=(X-Z)-Y
C.(X-Y)-Z=(X-Z)-(Y-Z)
D.(X-Y)-Z=X-(Y∪Z)
A.1atm=1033千克/米2
B.1mmHg=10.33/760mH2O
C.1atm=10.13kPa
D.1Mpa=1.033/0.1013kgf/cm2
A.Sm(T)≈Sm(298.15K)
B.K(T)≈K(298.15K)
C.△rGm(T)≈△rGm(298.15K)
D.△rHm(T)≈△rHm(298.15K)
A.4个
B.3个
C.2个
D.1个