Question

(9-6m)*(9+6m)+6m*(6m-5) при m=0,8

Answer 1

$(9 - 6m)(9 + 6m) + 6m(6m - 5)$
$81 + 54m - 54m - 36 {m}^{2} + 36 {m}^{2} - 30m$
$81 - 30m$
при m = 0,8:
$81 - 30(0.8) = 81 - 24 = 57$