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I want to plot a phase portrait, I think I need to use StreamPlot to do this, $$x'=x(a-bx-cy)$$ $$y'=y(d-ex-fy)$$ I know how to plot this with manipulate

Manipulate[Plot[{a/c-b/cx,d/f-e/fx,0},{x,-10,10}],{a,1,10},{b,1,10},{c,1,10},{d,1,10},{e,1,10},{f,1,10}]

but i cannot get the vectors to show direction nor can i graph the nullcline $x=0$

Manipulate[
 StreamPlot[{0, a/c - b/c*x, d/f - e/f*x}, {x, -3, 3}, {y, -3, 3}, 
  StreamScale -> Large, 
  PlotLabel -> 
   Row[{"a = ", a, " , b = ", b , ", c = ", c , ", d = ", d , 
     ", e = ", e, ", f = ", f }]], {a, 1, 10}, {b, 1, 10}, {c, 1, 
  10}, {d, 1, 10}, {e, 1, 10}, {f, 1, 10}]

but this gives me no image. Thank you.

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Manipulate[
 StreamDensityPlot[{x*(a - b*x - c*y), y*(d - e*x - f*y)}, {x, -3, 
   3}, {y, -3, 3}, StreamScale -> Large, 
  PlotLabel -> 
   Row[{"a = ", a, " , b = ", b, ", c = ", c, ", d = ", d, ", e = ", 
     e, ", f = ", f}]], {a, 1, 10}, {b, 1, 10}, {c, 1, 10}, {d, 1, 
  10}, {e, 1, 10}, {f, 1, 10}]

fig1

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