-7 1/2m+2 2/3m+1/6m=1 3/4×(-2 1/3)+4 1/5×2 5/6

(-7 1/2 + 2 2/3 + 1/6) * m = 1 3/4 * (-2 1/3) + 4 1/5 * 2 5/6;

(-(7 * 2 + 1)/2 + (2 * 3 + 2)/3 + 1/6) * m = (1 * 4 + 3)/4 * (-(2 * 3 + 1)/3) + (4 * 5 + 1)/5 * (2 * 6 + 5)/6;

(-15/2 + 8/3 + 1/6) * m = 7/4 * (-7/3) + 21/5 * 17/6;

(-15 * 3/6 + 8 * 2/6 + 1/6) * m = -7 * 7/(4 * 3) + (21 * 17)/(6 * 5);

(-45/6 + 16/6 + 1/6) * m = -49/12 + (7 * 17)/(2 * 5);

(-45 + 16 + 1)/6 * m = -49/12 + 119/10;

-28/6 * m = -490/120 + 1428/120;

-28/6 * m = 938/120;

m = - 938/120 * 6/28 = -(938 * 6)/(120 * 28) = -67/40.

Ответ: m = -67/40.