Bài 1:
\(\left(-0,125\right)\times7,9\times80\)
\(=\left(-0,9875\right)\times80\)
\(=79.\)
\(\left(0,125\right)\times1\times0,25\times8\times\left(-4\right)\)
\(=0,125\times0,25\times8\times\left(-4\right)\)
\(=0,03125\times8\times\left(-4\right)\)
\(=0,25\times\left(-4\right)\)
\(=\left(-1\right).\)
Bài 2:
\(x+\frac{8}{3}^2=\frac{1}{9}\)
\(x+16=\frac{1}{9}\)
\(x=\frac{1}{9}-16.MSC=9\)
\(x=\frac{1}{9}-\frac{144}{9}\)
\(x=\frac{-143}{9}.\)