Question

помогите решить 2,4,6

Answer 1

2)(2b+39)-(2b+1)-(4-5b)=2b+39-2b-1-4+5b=39-5+5b=34+5*0.5=34+2.5=36.5 4)b^2-4b-2-2b^2+1=-(b^2+4b+1)=-(25-20+1)=-(25-19)=-6 6)2-0.5c^2+c-c^2-2c^2+2=4+c-3.5c^2=4-2-3.5*4=2-14=-12