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Title: Use a system of linear equation to solve the problem #8? Post by: riyaz1203 on Aug 19, 2012 Suppose you bought supplies for a part. three rolls of streamers and 15 party jats cost $30. Later, you bought 2 rolls of streamers and 4 party hats for $11. How much did each roll of streamers cost? How much did each party hat cost?
Title: Use a system of linear equation to solve the problem #8? Post by: oascheri on Aug 19, 2012 3S + 15H = 30
2S + 4H = 11 6S + 30H = 60 6S + 12H = 33 Subtracting, 18H = 27 H = 27/18 = 1.50 2S + 4(1.50) = 11 2S = 11 - 6 = 5 S = 5/2 = 2.50 Hats are $1.50, streamers are $2.50 Title: Use a system of linear equation to solve the problem #8? Post by: oascheri on Aug 19, 2012 Hi,
3S + 15H = 30 2S + 4H = 11 Multiply first equation by 2 and the second equation by -3. then add and solve for H. Plug this answer back in and solve for S. 2(3S + 15H = 30) -3(2S + 4H = 11) 6S + 30H = 60 -6S - 12H = -33 ------------------------- 18H = 27 H = 1.50 If H = 1.50 and 2S + 4H = 11, then 2S + 4(1.50) = 11 2S + 6 = 11 2S = 5 S = 2.50 Hats are $1.50 and streamers are $2.50. <== ANSWER I hope that helps!! :-) Title: Use a system of linear equation to solve the problem #8? Post by: smilesalot891 on Aug 19, 2012 2 equations....
3s + 15p = $30 (Eq1) 2s + 4p = $11 (Eq2) We need to make one of the variables equal so we will multiply Eq2 by 3 and multiply Eq1 by 2 (this will make s the same value). 6s + 12p = $33 (Eq3) from Eq2 * 3 6s + 30p = $60 (Eq4) from Eq1 * 2 You should be able to do it from here in...... |