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k in (-oo:+oo)
1503/70 = 3*k+(3/7)*k+9/10 // - 3*k+(3/7)*k+9/10
1503/70-(3*k)-((3/7)*k)-(9/10) = 0
(-3/7)*k-3*k+1503/70-9/10 = 0
144/7-24/7*k = 0 // - 144/7
-24/7*k = -144/7 // : -24/7
k = -144/7/(-24/7)
k = 6
k = 6
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