Solve for x. A triangle equals 180

Match each equation with the operation you can use to solve for the variable. subtract 10. divide by 10. divide by 5. subtract 18. multiply by 10. add 18. add 10. multiply by 5. 5 = 10p arrowright p + 10 = 18 arrowright p + 18 = 5 arrowright 5p = 10 arrowright

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?