Setup weights and relations:

- Hamster weight: w
- Cat weight: w + 10

- Dog weight:w + 10

w + w + 10 + w + 10 = 35

Solve for

*w*in the equation w + w + 10 + w + 10 = 35

**Step 1: Group the w terms on the left hand side:**

(1 + 1 + 1)w = 3w

**Step 2: Group the constant terms on the left hand side:**

10 + 10 = 20

**Step 3: Form modified equation**

3w + 20 = + 35

**Step 4: Group constants:**

We need to group our constants 20 and 35. To do that, we subtract 20 from both sides

3w + 20 - 20 = 35 - 20

**Step 5: Cancel 20 on the left side:**

3w = 15

**Step 6: Divide each side of the equation by 3**

3w/3 = 15/3

w =

**5**

Source

Source