The equivalent exponential expression is 7^10. When an exponential expression is raised to a power, the result is an exponent with the same base and the product of the exponents.
To find the equivalent exponential expression, you have to multiply the raised powers 2 and 5 to get a product of 10. (7^2)^5 2*5=10 (7^2)^5 = 7^10
One inch of board is left if you subtract the two 3 inches pieces from the board the further subtract the 24 inches from the three 8 inches pieces you get 31-30