A) Substitute d=-20 into expression [tex]3d+1:[/tex]
[tex]3\cdot (-20)+1=-60+1=-59.[/tex]
B) For p=1.4 and q=1.3 the expression [tex]4p-2q[/tex] takes look
[tex]4\cdot 1.4-2\cdot 1.3=5.6-2.6=3.[/tex]
C) If [tex]b=\dfrac{1}{3}[/tex] and [tex]c=\dfrac{2}{3},[/tex] then
[tex]\dfrac{b}{c}=\dfrac{\dfrac{1}{3}}{\dfrac{2}{3}}=\dfrac{1}{3}:\dfrac{2}{3}=\dfrac{1}{3}\cdot \dfrac{3}{2}=\dfrac{1\cdot 3}{3\cdot 2}=\dfrac{1}{2}.[/tex]