(7-10k) - (8-8k) + (10k+6)=-8
7-10к-8+8к+10к+6=-8 -10к+8к+10к=-7-6-8+8 8к=-13 к=-13/8
(7-10k) - (8-8k) + (10k+6) = -8 7-10k-8+8k+10k+6=-8 8k=-13 k=- 13/8 k= - 1 5/8 k = - 1.625