What is the central idea of the speech? of The United Nations as a Bridge

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters

What is the solution for 6 - 7/8? explain the steps.

2and 3 are angles. complementary vertical congruent supplementary