I need help on 12 please 14 points

To determine the number of deer in a forest a forest ranger tags 280 and releases them back

Select the correct answer from each drop-down menu. a system of equations and its solution are given below. system a complete the sentences to explain what steps were followed to obtain the system of equations below. system b to get system b, the equation in system a was replaced by the sum of that equation and times the equation. the solution to system b the same as the solution to system a.]

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?