D is not an ordered pair.
The first step would be to subtract 1 from both sides, leaving you with 5x = 10.
It is a 3-4-5 right triangle
leg1 := 3x, leg2:=4x, hypotenuse:=5x
given hypotenuse = 75m
=> 5x=75
So, x= 75÷5 = 15
Therefore, leg1 = 3(15) = 45m.
leg2= 4(15) = 60m.