Question

Solve the following system of equations for c:
c + 6d = 31/2
d = 9 – 2c

Answer 1

multiply 1st equation by 2 to get rid of the fractions

2c+12d=31

plug in d

2c+12(9-2c)=31
2c+81-24c=31
22c=50
c=50/22
=25/11

Answer 2

Ohhh, thank you c:

Answer 3

Wait. Wouldn't 12 times 9 be 108, not 81?

Answer 4

yes you are right, I can't seem to multiply.

Answer 5

Hah, it's okay. Thanks though!