(4b-4)(4b +3)-4b(3b+4) при b=6.3

(4b-4)(4b +3)-4b(3b+4) = 4b^2 +12b -16b -12 - 12b^2 - 16b =4b^2 - 12b^2- 16b +12b -16b -12 = -8b^2 -20b -12 = -8×6,3^2 - 20×6,3 -12= -8×39,69 - 126 - 12 = -317,52 -138= -455,52