a basket of with 12 apples has a mass of 3105 grams. the same basket with 7 apples has a mass of 1,980 grams. each apple has the same mass. what is the mass of the basket?

Answer 1

a = mass of one aple

b = mass of basket

1 basket :

12 a + b = 3105 Subtract 12 a to both sides

12 a + b - 12 b = 3105 - 12 a

b = 3105 - 12 a

2 basket :

7 a + b = 1980

7 a + 3105 - 12 a = 1980

- 5 a + 3105 = 1980 Subtract 3105 to both sides

- 5 a + 3105 - 3105 = 1980 - 3105

- 5 a = -1125 Divide both sides by - 5

- 5 a / - 5 = - 1125 / - 5

a = 225 grams

b = 3105 - 12 a

b = 3105 - 12 * 225

b = 3105 - 2700

b = 405 grams

Proof :

12 a + b = 3105

12 * 225 + 405 = 3105

2700 + 405 = 3105

3105 = 3105

7 a + b = 1980

7 * 225 + 405 = 1980

1575 + 405 = 1980

1980 = 1980

Answer 2

1 basket :

12 a + b = 3105 Subtract 12 a to both sides

12 a + b - 12 a = 3105 - 12 a

b = 3105 - 12 a