Question

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A bag contains two steel balls and five brass balls. The total weight of the bag is 13 pounds. If two steel balls are added and two brass balls are removed, the bag’s weight decreases to 12 pounds.
If s is the weight of a steel ball and b is the weight of a brass ball, the system of linear equations representing this situation is 1. 2s + 5b = 12 and 4s + 3b = 13 , 2. 2s + 5b = 13 and 4s + 3b = 12 , 3. 4s + 5b = 13 and 2s + 3b = 12 , 4. 2s + 3b = 13 and 4s + 5b = 12.

Solving the system of linear equations, the weight of a steel ball is 1. 0.75 pound, 2. 1.5 pounds 3. 3 pounds 4. 4 pounds. and the weight of a brass ball is 1. 1 pound. 2. 2 pounds 3. 3 pounds 4. 4 pounds.

Answer 1

Number 2

Explanation:

2s + 5b = 13

+2s -2b

4s + 3b = 12

Answer 2

2s + 5b = 13

4s + 3b = 12

s = 1.5 pounds

b = 2 pounds

Explanation:

2s + 5b = 13 (1)

(2+2)s + (5-2)b = 12

4s + 3b = 12 (2)

2s = 13 - 5b

2(13 - 5b) + 3b = 12

26 - 10b + 3b = 12

7b = 14

b = 2

2s = 13 - 5(2) = 3

s = 1.5