Question

Herschel uses an app on his smartphone to keep track of his daily calories from meals. one day his calories from breakfast were 128 more than his calories from​ lunch, and his calories from dinner were 400 less than twice his calories from lunch. if his total caloric intake from meals was 1932​, determine his calories for each meal.

Answer 1

Answer:

The correct answer is:

• Breakfast: 679 calories

• Lunch: 551 calories

• Dinner: 702 calories

Explanation:

For the example we have to consider the calories from breakfast, lunch, and dinner as follows:

• Breakfast: x + 128  

• Lunch: x

• Dinner: 2x – 400

According the problem, the total of calories consumed that day was 1932. Thus:

Breakfast + Lunch + Dinner = 1932

(x + 128) + x + (2x – 400) = 1932

4x – 272 = 1932

4x = 2204

x = 551

Then,

• Breakfast: x + 128 = 679 calories

• Lunch: x = 551 calories

• Dinner: 2x – 400 = 702 calories

Answer 2

Let the number of calories from lunch be called L. As such, breakfast is then L + 128, and dinner is 2L - 400. We can then sum the three meals and equate it to the total caloric intake, the known value of 1932.
   So: 1932 = L + L + 128 + 2L - 400 = 4L - 272.
   Lunch = 551
 Breakfast = 551 + 128 = 679
 Dinner = 2*551 - 400 = 702