The birth rate in a certain city is described by the following function . the city's death rate is given by . here, t is measured in years, and t = 0 corresponds to the start of the year 1990. the birth and death rates are measured in thousands of births or deaths per year. at the start of 1990, the population of the city is 450 thousand. enter all the following answers correct to two decimal places.

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality