Пошаговое объяснение:
если n=0,21.
-0,5(1-3n)+4(0,2n-0,1)-(0,1-0,7n) =
= -0.5 (1-3*0.21) + 4(0.2*0.21-0.1)-(0.1-0.7*0.21)=
= -0.5 (1-0.63) + 4(0.042-0.1) - (0.1- 0.147) =
= - 0.5 * 0.37 + 4*(-0.058) +0.047 =
= - 0.185 - 0.232 + 0.047 = - 0.37
