Question

Chứng minh đẳng thức sau:

a.(b-c)-a(b+d)=a(c+d)

giúp mk nhé

Answer 1

Có \(a\left(b-c\right)-a\left(b+d\right)\)

\(\Rightarrow ab-ac-ab-ad\)

\(\Rightarrow ac+ad\)

\(\Rightarrow a\left(a+d\right)\)

Answer 2

Ta có: a.(b-c) - a.(b+d) = (ab - ac) - (ab+ad) = ab -ac - ab - ad

= ab - ab +ac+ad = ac+ad

Ta lại có: a(c+d) = ac+ad

Vậy a(b-c) - a(b+d) = a(c+d)

Answer 3

\(a\left(b-c\right)-a\left(b+d\right)\)

\(\Rightarrow ab-ac-ab-ad\)

\(\Rightarrow\left(ab-ab\right)+\left(ac+ad\right)\)

\(\Rightarrow a\left(c+d\right)\)

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