1.若不等式（x+2）/k＞1+（x-3）/k²的解为x＞3,求k解不等式组56x²+ax＜a²_数学解答

(1)解析：(x+2)/k＞1+(x-3)/(k^2) (k≠0)即(xk+2k)/(k^2)-(x-3)/(k^2)＞1即[k(x-1)+(2k+3)]/(k^2)＞1即kx＞k^2-k+3∵其解为x＞3故k＞0即x＞(k^2-k+3)/k故(k^2-k+3)/k＝3 (k＞0)即k^2-4k+3＝0即(k-1)(k-3)＝0故k＝1或...解不等式组56x²+ax＜a²解析：56x^2+ax-a^2<0即(7x-a)(8x+a)<0即[x-(a/7)][x+(a/8)]<0①当a>0，a/7>-a/8，故解集为-a/8a/7，故解集为a/7