Let z be the unknown number.

−61 times the difference between a number and 56 is equal to the number plus −28

Is this correct:
-61(z-56)=z-28

From the way you originally have it stated, I would agree.

-3+x=-x+5

Yes, that's correct! The equation -61(z-56) = z-28 represents the statement "−61 times the difference between a number (z) and 56 is equal to the number (z) plus −28".

To solve this equation, you can follow these steps:

1. Distribute -61 to both terms inside the parentheses:
-61 * z + 61 * 56 = z - 28

2. Simplify both sides of the equation:
-61z + 3436 = z - 28

3. To isolate the variables, combine like terms:
-61z - z = -28 - 3436
-62z = -3464

4. Divide both sides of the equation by -62 to solve for z:
z = (-3464) / (-62)
z ≈ 55.87

Therefore, the unknown number z is approximately 55.87.