50.4/0.45=112!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1)раскрыть скобки 25-20a-12a-78= -32a-53
если a=0,5 то -32*0,5-53= -64-53=-117
-10(0.7-3b)+14b+13 = -7+30b+14b+13=44b+6
b=-1/4=-0.25
44*(-0/25)+6=-11+6=-5
Ответ:-5.
(5-t)(-t-5)-(4+t)² = (-t)²-25-(16+8t+t²) = (-t)²-25-16-8t-t² = - 41 - 8t