one pan pizza and two beef burritos provide 1980 calories. two pan pizzas and one beef burrito provide 2670 calories. find the calories content of each item

Question

one pan pizza and two beef burritos provide 1980 calories. two pan pizzas and one beef burrito provide 2670 calories. find the calories content of each item

Answer 1

Let the calorie count of 1 pan pizza be P

 

Let the calorie count of 1 beef burrito be B

 

P + 2B = 1980                 (1)

 

2P + B = 2670                 (2)

 

Substitute for P in (1); P = 1980 - 2B     (3)

 

eliminating P in (2); 2(1980 - 2B) + B = 2670

 

3960 -4B + B = 2670

 

3960 - 2670 = 4B - B   rearranging

 

1290 = 3B; B = 1290/3 = 430

 

From (3); P = 1980 -2B = 1980 - 2*430 = 1120

 

Checking answer ;1120 + 2*430 = 1980 (proven)

 

                           and   2*1120 + 430 = 2670 (proven)

Answer 2

 

First, you should select variables for what you are solving for.

 

Pan pizza calories = P

Beef burrito calories = B

 

One pan pizza and two beef burritos provide 1980 calories.

 

P + 2B = 1980

 

two pan pizzas and one beef burrito provide 2670 calories.

 

2P + B = 2670

 

find the calories content of each item.

 

Now you have two equations in two variables. Use substitution to solve the problem.

 

2P + B = 2670 

-2P           -2P

B = 2670 - 2P

 

put this into the first equation for B

 

P + 2B = 1980

 

P + 2(2670 - 2P) = 1980

 

Then solve for P

 

P + 5340 - 4P = 1980

5340 - 3P = 1980

5340 - 1980 = 3P

3360 = 3P

1120 = P

 

The pan pizza is 1120 calories

Substitute this number into one of the original equations for P and solve for B

 

2P + B = 2670

2(1120) + B = 2670

2240 + B = 2670

B = 2670 - 2240

B = 430

 

The burrito is 430 calories