You need to make two equations-
Use b for butternut squash and z for zucchini.
2b+4z = $6.96
3b=6z
Solve for one of the variables in the second equation ( I will solve for b)
3b/3=6z/3
b=2z
Plug it in-
2(2z)+4z =$6.96
4z+4z=$6.96
8z =$6.96
8z/8 = 6.96/8
z= .87
Plug in again - (b=2z)
b= (2)(.87)
b= $1. 74
So the zucchini is 87 cents and the butternut squash is $1.74 (each)