y=(x-1) y=0 =3

I think you might mean: find the area bounded by the curves y = x − 1, y = 0, and x = 3.

If so:

• Intersection of y = x − 1 with y = 0 is at x = 1 (point (1, 0)).
• The region bounded by x = 1, x = 3, y = 0, and y = x − 1 is a triangle with vertices (1,0), (3,0), (3,2).

Area:

• Geometric: base = 3 − 1 = 2, height = y at x = 3 = 3 − 1 = 2. Area = 1/2 × base × height = 1/2 × 2 × 2 = 2.
• Or via integral: ∫ from 1 to 3 of (x − 1) dx = [0.5x^2 − x]1^3 = 2.

Answer: 2 (square units).

If your problem was different, please share the exact statement and I’ll adjust.