Jim’s family is choosing whether to go to a restaurant for lunch or for dinner. The cost of a salad is $7 at lunch and $9 at din
ner. The cost of a steak is $10 at lunch and $12 at dinner. Each person will choose either a salad or a steak regardless of the mealtime. Jim calculates the food bill to be $41 if they go during lunch and $51 if they go during dinner. How many people will choose a salad? 2
3
4
5
To answer the problem above we let x be the number of people who prefers salad and y be the number of people who chose steak. For lunch they will be spending $41. That is,
7x + 10y = 41
Now, for dinner they will be spending $51. That is,
9x + 12y = 51
The values of x and y from both equations are 3 and 2, respectively. Therefore, 3 people will choose a salad