Since 60 minutes equal 1 hour, in 2 hours, Eliza ironed blouses for 2 x 60 = <<2*60=120>>120 minutes.
Eliza can iron 120 / 15 = <<120/15=8>>8 blouses.
Since 60 minutes equal 1 hour, in 3 hours, Eliza ironed dresses for 3 x 60 = <<3*60=180>>180 minutes.
Eliza can iron 180 / 20 = <<180/20=9>>9 dresses.
In total, Eliza ironed 8 + 9 = <<8+9=17>>17 pieces of clothes.
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