Complete the Expression: (7×8) Raised to Power (b+a)

To solve this problem, we'll follow the steps below:

First, recognize that the expression given is $(7 \times 8)^{b+a}$. We aim to use the exponent rule known as the power of a product, which states that $(xy)^n = x^n \times y^n$.

Applying this rule to the problem at hand, we have:

$(7 \times 8)^{b+a} = 7^{b+a} \times 8^{b+a}$.

Thus, the expression is expanded to show each base (7 and 8) raised to the combined power of $b+a$.

Checking the choices provided, the expanded expression matches option 2.

Therefore, the correct expression is $7^{b+a}\times8^{b+a}$.