Verified Answer :

2/3=1/2q

q=(2/3)/(1/2)

q=(2/3)(2/1)

q=4/3=3/3+1/3

q=1.333...

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2/3=-1/2q

q=(2/3)/((-1)/2)

q=(2/3)(2/(-1))

q=-4/3=-3/3-1/3

q=-1.333...

AL2006

It appears in two different ways up there - once with 1/2q  and the other with -1/2 q.

If it's  1/2q , then multiply each side of the equation by  2 .

If it's  -1/2q , then multiply each side of the equation by  -2 .