Question

daca a + b = -2/3 si b+ c = -1/2 atunci a-c

Answer 1

$\bf a+b=-\dfrac{2}{3} \:\:|\cdot 6\:\:\text{\it inmultim toata relatia cu 6}$

$\bf 6a+6b=-4$

$\bf b+c=-\dfrac{1}{2} \:\:|\cdot 6\:\:\text{\it inmultim toata relatia cu 6}$

$\bf 6b+6c=-3$

scadem cele 2 relatii si vom avea:

$\bf 6a+6b=-4$

$\bf 6b+6c=-3$         ( - )

$\bf 6a +6b -6b -6c= -4 - (-3)$

$\bf 6a -6c= -4 +3$

$\bf 6(a-c)= -1\:\:\:|:6$

$\boxed{\bf a-c= -\dfrac{1}{6}}$

Answer 2

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