1)6 a+4 b+3 b-8 a при a=1,b=0.52; 6а-8а+7b;
7*0,52-2*1; 3,64-2=1,64; ////
2) 7.4 х - 2.7 у + 6.3 у - 9.6 х при х = -5; при у = 2; 7,4x-9,6x+6,3y-2,7y; 3,6y-2,2x; 3,6*2-2,2*(-5);
7,2+11=18,2; //////
3) 1/2 а + 3/8 b - 2/3 a - b при а = 3; b = 4.;
1/2a-2/3a+3/8b-b=3/6a-4/6a+3/8b-8/8b=-1/6a-5/8b; -1/6*3/1-5/8*4/1=-1/2-5/2=-6/2=-3