\(a.\)
Tại \(x=5\)
\(\Rightarrow\left(3.5-5\right)-\left(30+4.5\right)-\left(5+15\right)\)
\(=10-50-20=-60\)
\(b.\)
Tại \(x=\left(-1\right)^{2015}\)
\(\Rightarrow\left|5.\left(-1\right)\right|-3.\left(-1\right)-2017\)
\(=-5+3-2017\)
\(=-2019\)
a) \(\left(3x-5\right)-\left(30+4x\right)-\left(x+15\right)\) . Với x = -5
Ta có : \(\left(3.-5-5\right)-\left(30+4.-5\right)-\left(-5+15\right)\)
\(=\left(-10\right)-10-10\)
\(=-30\)
b) \(\left|5-x\right|-3x-2017\) với \(x=\left(-1\right)^{2015}=-1\)
Ta có : \(\left|5-\left(-1\right)\right|-3.\left(-1\right)-2017\)
\(=\left|6\right|-\left(-3\right)-2017\)
\(=9-2017\)
\(=-2008\)
