(U+7)(u-1)

To simplify the expression (u+7)(u-1), we can use the distributive property.

First, multiply the first terms in each set of parentheses:

u \cdot u = u^2

Next, multiply the outer terms:

u \cdot (-1) = -u

Then, multiply the inner terms:

7 \cdot u = 7u

Finally, multiply the last terms in each set of parentheses:

7 \cdot (-1) = -7

Now, combine all the terms:

u^2 - u + 7u - 7

Simplify further by combining the like terms:

u^2 + 6u - 7

Therefore, the simplified expression is:

Answer: u^2 + 6u - 7