<prompt> Makadirio ya beginpmatrix a 7 endpmatrix kwenye beginpmatrix -1 4 endpmatrix nifrac2617 anzapmatrix -1 4 endpmatrix.Tafuta a.  <response>: Makadirio ya beginpmatrix a 7 endpmatrix kwenye beginpmatrix -1 4 endpmatrix imetolewa nafracanzapmatrix a 7 mwishopmatrix cdot anzapmatrix -1 4 mwishopmatrixleft anzapmatrix -1 4 mwishopmatrix kulia2 anzapmatrix -1 4 mwishopmatrix frac-a 2817 startpmatrix -1 4 endpmatrix.Kwa hivyo, tunataka frac-a 2817 frac2617. Kutatua, tunapata a 2. 