Respuesta :
Answer:
trail mix costs 1.00 per pound
jelly beans costs 3.50 per pound
Step-by-step explanation:
t = cost of trail mix
b = cost of jelly beans
3t+8b = 31
5t+2b = 12
Multiply the second equation by -4
-4(5t+2b = 12)
-20t+-8b = -48
Add this to the first equation
3t+8b = 31
-20t+-8b = -48
-------------------------
-17t = -17
Divide by -17
t = 1
Now we can find b
3t+8b = 21
3(1) +8b = 31
3+8b =31
Subtract 3
8b = 31-3
8b = 28
Divide by 8
b = 28/8
b = 7/3
b = 3.50
Let trail mix be x and jelly beans be y
The equations are
- 3x+8y=31-(1)
- 5x+2y=12-(2)
Multiplying (1) by 1 and (2) by 4
- 3x+8y=31---(3)
- 20x+8y=48--(4)
Subtracting
[tex]\\ \sf\longmapsto -17x=-17[/tex]
[tex]\\ \sf\longmapsto x=1[/tex]
Putting in eq(2)
[tex]\\ \sf\longmapsto 5(1)+2y=12[/tex]
[tex]\\ \sf\longmapsto 2y=7[/tex]
[tex]\\ \sf\longmapsto y=7/2[/tex]