Answer:
Perimeter = 4.2y - 14
Step-by-step explanation:
Perimeter of a triangle = the sum of the three sided of the triangle.
In an isosceles triangle, there are two equal sides and a base.
Perimeter = (0.6y - 7) + (0.6y - 7) + 3y
Perimeter = (0.6y + 0.6y + 3y) - 7 - 7
Perimeter = 1.2y + 3y - 14
Perimeter = 4.2y - 14