-(12z+3t)^2=-(144z^2+72zt+9t^2)=-144z^2-72zt-9t^2
Ответ:
2/5*(b+5)-3/10(5b-1)=4
(2b+10)/5-(15B-3)/10=4
(4b+20-15b+3)/10=4
23-11b=40
-11b=17
b=-17/11=-1(6/11)