Lenny is making his own laundry soap. The recipe calls for two parts, borax, two parts washing soda, and one part soap flakes. If Lenny use is 7 cups of soap flakes, how many cups of borax and washing soda combine does he need?
If Lenny is using 7 cups of soap flakes, and the recipe calls for one part soap flakes, then the total number of parts in the recipe is 2+2+1 = <<2+2+1=5>>5 parts.
So one part is equal to 7/5 = <<7/5=1.4>>1.4 cups.
Therefore, Lenny needs 1.4*2 = <<1.4*2=2.8>>2.8 cups of borax.
And he also needs 1.4*2 = <<1.4*2=2.8>>2.8 cups of washing soda. Answer: \boxed{2.8}.