Answer
$\color{blue}{2z-z^{3/2} -z^2}$
Work Step by Step
RECALL:
$(a+b)(c+d)=ac + ad + bc + bd$ (more popularly known as the FOIL method.
Use the formula above to obtain:
$=2z^{1/2}\cdot z^{1/2} + 2z^{1/2} \cdot (-z) + z \cdot z^{1/2} + z \cdot (-z)$
Use the rule $a^m \cdot a^n = a^{m+n}$ to obtain:
$=2z^{1/2+1/2} -2z^{1/2+1}+z^{1+1/2}-z^{1+1}
\\=2z^1-2z^{3/2} + z^{3/2} -z^2
\\=\color{blue}{2z-z^{3/2} -z^2}$