What goes in the parenthesis?

Select the correct answer from each drop-down menu. rewrite the formula to find voltage. the formula for electrical power (p, in watts) is where v is the voltage in volts and r is the resistance in ohms. for a particular brand of water heater, r is 32 ohms and p is 0.5 watts. the formula to find v is , and the voltage at which the heater operates is volts.

To prove that def ~ gfh by the sss similarity theorem using the information provided in the diagram, it would be enough additional information to know that

What is the value of x when x + 7 = 21?