In each of the possible answer choices, substitute 5 for k and determine whether the resulting equation is true or false.
4(k−1.3)=15.12 becomes 4(5-1.3) = 15.12, or 4(3.7) = 15.12 FALSE
1.1k−1.8=7.3 becomes 1.1(5) - 1.8 = 7.3 FALSE
1.4(0.7k+2)=2.1 becomes 1.4(0.7*5+2) = 2.1 FALSE
1.8k+3.2=12.2 becomes 1.8(5) + 3.2 = 12. 2 TRUE