## mitchelsewbaran 2 years ago Write a system of equations for the following situation. Sharon has some \$1 bills and some \$5 bills. She has 14 bills which total to a value of \$30.

1. Kuoministers

let \$1 = x and \$5 = y ok? so 1x + 5y = 30 now that is one equation

2. mitchelsewbaran

right

3. Kuoministers

any idea what the 2nd one is?

4. mitchelsewbaran

14x+14y=30?

5. Kuoministers

x + y = 14

6. Kuoministers

now we use a method to find x and y? which do you like ^^ elimination? substitution?

7. mitchelsewbaran

the 1st one

8. Kuoministers

awsome (so much easier) x + 5y = 30 x + y = 14 we subtract x from x vertically. 4y = 16

9. mitchelsewbaran

y=4

10. Kuoministers

now i hope you can figure it out. once you find y sub y into the equation

11. mitchelsewbaran

isnt that for the substitution method?

12. Kuoministers

nope

13. Kuoministers

we use the elimination then we sub y into the equation

14. Kuoministers

if we did substitution we would make y the subject then get y THEN we would sub y into equation to get x

15. mitchelsewbaran

which equation should i plug the 4 in for y?

16. Kuoministers

any :)

17. Kuoministers

x + y = 14 would just be easier though

18. mitchelsewbaran

ok ill go for that. I got 10 for x

19. Kuoministers

good so we can conclude x = 10 and y = 4

20. mitchelsewbaran

srry i didn't get the 2nd equation when u asked :(

21. Kuoministers

mhm what equation?

22. Kuoministers

x + y = 14?

23. mitchelsewbaran

yea

24. Kuoministers

well there is some \$1 and \$5 bills yea... and they add to 14. we said that \$1 is x and \$5 is y. so x + y is equal to 14.

25. mitchelsewbaran

ok

26. Kuoministers

thank you!!