Resposta :
[tex]\large\boxed{\begin{array}{l} \sf a) \: \dfrac{x}{8} = \dfrac{7}{2} \\ \\ \sf \: 2x = 8 \times 7 \\ \\ \sf \: 2x = 56 \\ \\ \sf \: x = \dfrac{56}{2} \\ \\ \boxed{ \sf{x =28}} < < \sf{resposta}\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf {b) \: \dfrac{x}{9} = \dfrac{8}{2} } \\ \\ \sf \: 2x = 9 \times 8 \\ \\ \sf \: 2x = 72 \\ \\ \sf \: x = \dfrac{72}{2} \\ \\ \boxed{ \sf{x = 36}} < < \sf{resposta}\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf{c) \: \dfrac{2x}{9} = \dfrac{8}{2} } \\ \\ \sf \: 4x = 8 \times 9 \\ \\ \sf \: 4x = 72 \\ \\ \sf \: x = \dfrac{72}{4} \\ \\ \boxed{ \sf{x = 18}} < < \sf{resposta}\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf{d) \: \dfrac{4x}{8} = \dfrac{7}{2} } \\ \\ \sf \: 8x = 7 \times 8 \\ \\ \sf \: 8x = 56 \\ \\ \sf \: x = \dfrac{56}{8} \\ \\ \boxed{ \sf{x = 7}} < < \sf{resposta}\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf{e) \: \dfrac{3x}{8} = \dfrac{6}{2} } \\ \\ \sf \: 6x = 6 \times 8 \\ \\ \sf \: 6x = 48 \\ \\ \sf \: x = \dfrac{48}{6} \\ \\ \boxed{ \sf{x = 8}} < < \sf{resposta}\end{array}}[/tex]