Use the substitution method to solve:
7b + 4c = 8.77
14b + 8c = 15.80
Check Format
Equation 1 is in the correct format.
Check Format
Equation 2 is in the correct format.
Rearrange Equation 2 to solve for b:
14b + 8c = 15.80
Subtract 8c from both sides to isolate b:
14b + 8c - 8c = 15.80 - 8c
14b = 15.80 - 8c
Now divide by 14:
| 14b | |
| 14 |
| = |
| 15.80 - 8c |
| 14 |
Revised Equation 2:
| b = | 15.80 - 8c |
| 14 |
Plug Revised Equation 2 value into b:
7(b) + 4c = 8.77
7 * ((15.80 - 8c)/14) + 4c = 8.77
((110.6 - 56c)/14) + 4c = 8.77
Multiply equation 1 through by 14
14 * (((110.6 - 56c)/14) + 4c = 8.77)
14 * (((110.6 - 56c)/14) + 4c = 8.77)
110.6 - 56c + 56c = 122.78
Group like terms:
-56c + 56c = 122.78 - 110.6
0c = 12.18
Divide each side by 0
| 0c | |
| 0 |
| = |
| 12.18 |
| 0 |
| c = | 12.18 |
| 0 |
Because c = 12.18/0, our system of equations has no solutions