Question

11+4a+4b, якщо a+b= -1,5

Answer 1

$\displaystyle\bf\\a+b=-1,5\\\\\\11+4a+4b=11+(4a+4b)=11+4\cdot\underbrace{(a+b)}_{-1,5}=\\\\=11+4\cdot(-1,5)=11-6=5$