T
trang6ba1
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Đề Bài: CMR ta có tỉ lệ thức a/b=c/d nếu có một trong các đẳng thức sau
(a+b+c+d)(a-b-c+d)=(a-b+c-d)(a+b-c-d)
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Mọi người giúp mình nha!!!!!
(a+b+c+d)(a-b-c+d)=(a-b+c-d)(a+b-c-d)