28-6x меньше x
28 меньше х+6х
28 меньше 7х
х меньше 4
A) mn+4m+2n+8= m*(n+4)+2*(n+4)=(m+2)(n+4)
b) <span>3ap-4bp+3aq-4bq = 3a(p+q)-4b(p+q)=(3a-4b)(p+q)</span>
P=6m+4+3m+5+6m+6+5m-1=(6m+3m+6m+5m)+(4+5+6-1)=20m+14
Решение7/7-х. + х^2+49/х^2-49 при х= - 14.
7/(7 - х). + (х^2 + 49)/(х^2 - 49) = 7 / (7 - x) - (x² + 49) / [(7 - x)*(7 + x)] == [7*(7 + x) - x² + 49] / [(7 - x)*(7 + x)] = [49 + 7x - x² - 49] / [(7 - x)*(7 + x)] == [x*(7 - x)] / [(7 - x)*(7 + x)] = x / (7 + x)при х= - 14. - 14 / (7 - 14) = - 14/(-7) = 2