System of equations word problem

Question

The perimeter of a triangle is 48cm. The triangle is isosceles now, but if it's base we're lengthened by 6cm and each leg were shortened by 6cm, it would be equilateral. Find the base of the original triangle.

Answer 1

First, you employed it's where you meant its (possessive).

Second, did you draw & label two triangles?

First triangle: legs x, x, base b.

Second triangle: legs x, x, base b+6.

Using facts given in statement of question:

2x+b = 48

x=b+6.

A little system of 2 equations, 2 unknowns; you can solve it.