Simplify the following expressions and then check your answers with a scientific calculator.

1. $\left(16 + 2\right) · \left(−3−1\right)$

   Step 1(a):

   $18\left(-4\right)$

2. $−6 + 7 · 5$

   Answer (b):

   $29$

3. $4\left(−6\right) − \left(−11\right) + 6\left(1 − 5\right)$

   Hint (c):

   Circling terms should make this one easier.

   $\enclose{circle}[mathcolor="blue"]{\color{black}{4\left(-6\right)}}-\enclose{circle}[mathcolor="blue"]{\color{black}{\left(-11\right)}}+\enclose{circle}[mathcolor="blue"]{\color{black}{6\left(1-5\right)}}$