若a^2+b^2=1/4,a-b=1/2,则a+b的值为A-1/2 B1/2 C1 D2
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![若a^2+b^2=1/4,a-b=1/2,则a+b的值为A-1/2 B1/2 C1 D2](/uploads/image/z/10165299-51-9.jpg?t=%E8%8B%A5a%5E2%2Bb%5E2%3D1%2F4%2Ca-b%3D1%2F2%2C%E5%88%99a%2Bb%E7%9A%84%E5%80%BC%E4%B8%BAA-1%2F2+B1%2F2+C1+D2)
若a^2+b^2=1/4,a-b=1/2,则a+b的值为A-1/2 B1/2 C1 D2
若a^2+b^2=1/4,a-b=1/2,则a+b的值为
A-1/2 B1/2 C1 D2
若a^2+b^2=1/4,a-b=1/2,则a+b的值为A-1/2 B1/2 C1 D2
∵a^2+b^2=1/4
a-b=1/2
两边平方
a²-2ab+b²=1/4
∴ab=0
(a+b)²=a²+b²+2ab=a²+b²=1/4
∴a+b=-1/2(舍去)或a+b=1/2
选B