Answer:
D. (7 ÷ 9) × 100
Explanation:
In order to solve this problem we need the answers of the problem, performing an internet search this problem is found, with the different answer options
A. (7 − 9) × 100
B. (9 − 7) × 100
C. (9 ÷ 7) × 100
D. (7 ÷ 9) × 100
Returning to the problem of the total energy of 9V only 7 volts were used. If we make a rule of three we realize that:
[tex]100 = 9V\\x = 7\\x = \frac{7*100}{9} \\[/tex]
x = 77.77%
In this way we determine that the answer is D.