SOLUTION: meg sold 3 packs of gum and 3 sticks of gum for $48. joe sold 7 packs and 9 sticks for $132. what is the cost of one pack and one stick of gum?
Question 825550: meg sold 3 packs of gum and 3 sticks of gum for $48. joe sold 7 packs and 9 sticks for $132. what is the cost of one pack and one stick of gum? Answer by TimothyLamb(4379) (Show Source):
You can put this solution on YOUR website! ---
x = price per pack
y = price per stick
---
3x + 3y = 48
7x + 9y = 132
---
copy and paste the above linear system in standard form into this matrix-method solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution by matrix method:
x = 6
y = 10
---
system matrix
3 3
7 9
---
inverse of system matrix
1.5 -0.5
-1.1666667 0.5
---
determinant of system matrix = 6
---
now solve by elimination method:
---
(3x + 3y = 48)7
(7x + 9y = 132)-3
---
21x + 21y = 336
-21x - 27y = -396
---
add the system:
-6y = -60
---
y = 10
---
3x + 3y = 48
3x + 3(10) = 48
3x = 18
---
x = 6
---
solution by elimination method:
x = 6
y = 10
---
NOTE:
solution by matrix method agrees with solution by elimination method
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 4-equations 4-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
