Question

daca a x b=-2/5 si a x c=1/3, atunci:
a) a x(b+c)=?
b) a x(b-c)=?
x=>ori
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Urgent!!!!!!!!!!

Answer 1

a x b=-2/5 ⇒ a x c=1/3a x(b+c)=a×b+a×c=(-2/5)+(1/3)=aducem la acelasi numitor: [( -2×3)-(5×1)]/15=-(6-5)/15=1/15

a) a x(b+c)=1/15

b) a x(b-c)=?  ;  a x(b-c)=(a×b)-(a×c)=-2/5-1/3=aducem la acelasi numitor
(-2×3)-(1×5)]/15=(-6-5)/15=-11/15

a x(b-c)= - 11/15

Answer 2

 [tex]a)\;a\cdot(b+c)=a\cdot{b}+a\cdot{c}=\frac{-2}{5}+\frac{1}{3}=\,\,\frac{-6+5}{15}=-\frac{1}{15}\;;\\ b)\;a\cdot(b-c)=a\cdot{b}-a\cdot{c}=\,-\,\frac{2}{5}-\frac{1}{3}=-\frac{11}{15}\;;[/tex]