A basket with 12 apples has a mass of 3105 grams. The same basket with 7 apples has a mass of 1980 grams. Each apple has the same mass. What is the mass of the basket?
b = mass of the basket
a = mass of the aple
b + 12 a = 3105 Subtract 12 a to both sides
b + 12 a - 12 a = 3105 - 12 a
b = 3105 - 12 a
b + 7 a = 1980
3105 - 12 a + 7 a = 1980
3105 - 5 a = 1980 Subtract 1980 to both sides
3105 - 5 a - 1980 = 1980 - 1980
1125 - 5 a = 0 Add 5 a to both sides
1125 - 5 a + 5 a = 0 + 5 a
1125 = 5 a Divide both sides by 5
1125 / 5 = 5 a / 5
225 = a
a = 225 grams
b = 3105 - 12 a
b = 3105 - 12 * 225
b = 3105 - 2700
b = 405 grams
Mass of the basket = 405 grams