Question

Solve a system of equations using substitution: word problems

Lina is comparing the cost of a fresh lobster dinner at two different restaurants. The first restaurant charges $39 for the meal, plus $7 per kilogram for the lobster she picks. At the second restaurant, Lina would pay $2 per kilogram for the lobster, in addition to $44 for the meal. Lina realizes that, in theory, dinner at both restaurants could cost the same amount if the lobster had a certain weight. How much would Lina pay for her dinner? What is the weight?


Dinner would cost $___ at either restaurant if Lina's lobster weighed _____ kilograms.
Submit

Answer 1

restaurant 1 : y = 7k + 39
restaurant 2 : y = 2k + 44

7k + 39 = 2k + 44
7k - 2k = 44 - 39
5k = 5
k = 5/5
k = 1

y = 2k + 44
y = 2(1) + 44
y = 2 + 44
y = 46

Dinner would cost $ 46 at either restaurant if Lina's lobster weighed 1 kilogram.