Step-by-step explanation and answer:
The given equations P=2T=3Q can be split up into
P=2T..................(1)
P=3Q................(2)
since they are all equal.
Rewrite the given equation
3Q + 4T = 26 .............(3)
as
3Q + 2(2T) = 26 ...........(4)
and substitute (1) and (2) into (4)
P + 2(P) = 26 .................(5)
Multiply (5) by two to get
6P = 2*26 = 52 ..............(6)
as given.