Question

double check my work? A store is having a sale on chocolate chips and walnuts. For 6 pounds of chocolate chips and 2 pounds of walnuts, the total cost is $14 . For 3 pounds of chocolate chips 5 and pounds of walnuts, the total cost is $20. Find the cost for each pound of chocolate chips and each pound of walnuts.

I made the equation 6c + 2w = 14, solved for both variables and got c = 2 and w = 1. However, when I substitute those variables into the second equation (3c + 5w = 20), the variables do not work.

Answer 1

you started out right at the start but you need to solve the 2 equations simultaneously

Answer 2

should i combine like terms from both equations?

Answer 3

start with the first equation, you need to either find c or w. So just say we will find c...

Answer 4

6c + 2w = 14

so 6c = 14 - 2w

Answer 5

c = 3?

Answer 6

nevermind, I solved mine a different way. But the equation you wrote would be c = 2?

Answer 7

actually, find W, its easier
and less confusing 4 u

Answer 8

6c + 2w = 14

so 2w = 14 - 6c

Answer 9

w = 7 - 3c

Answer 10

can u see how i got W?

Answer 11

the you have to sub W= 7-3c into the second equation

Answer 12

yes, I understand

Answer 13

3c + 5(7 - 3c) = 20?

Answer 14

yep

Answer 15

now expand it and find c

Answer 16

3c + 5(7 - 3c) = 20
3c + 35 - 15c = 20
35 - 12c = 20
-35 -35

-12c/-12 = -15/-12

I think I did something wrong. Is it okay if i got a decimal? 1.25

Answer 17

yeah that looks ok, now sub c = 1.25 into one of the original formulas to find w